Documenting the engine swap I’m in the middle of on my 85. Car is a VIN G, which means HO 305 with carb. Original 305 was replaced around 2011, based on paperwork that came with the car when I purchased it in 2019. Replacement was a plain-Jane 350 Jasper engine that developed a freeze crack on the driver side of the block. So... built my first engine - a roller cam 350 - spec'd for TPI.

Here is link to the story of the rebuild: TGO Link

Shortly after the purchase of the 85, I picked up an 88 parts car because it had the TPI fueling I intended to eventually swap onto the car. That has been great, as I've used the original wiring harness and fuel lines, plus the lower manifold (have polished runners and plenum I did even further back from a 91 Corvette).

Process started at end of February – I’ve been setting goals almost every day on what to accomplish, so progress has been slow, but steady. I’d mentally broken the swap down into four phases: Removal, Cleaning, Conversion to TPI, and Installation. Lots of pictures along the way, has been helpful as things start going back in. I finally decided to stop procrastinating and get started. Was hard, because the car runs really well. If it wasn’t for the coolant leak, I’d keep running the stuffing out of the current block.

Last picture of the old engine in the car

 

Every journey begins with a single step. I kept telling myself that as I started prepping the car and getting it up on the Quick Jacks for an extended period. I’d been making a list of what needed to be done and removed from the car for the swap – drain coolant and transmission oil, remove driveshaft, etc. First stumbling block I came across was that the aluminum driveshaft I polished and installed last year is too large in diameter to remove without taking off either exhaust or torque arm. Since the latter had to come out anyway, it got moved up in the removal order.

Once torque arm and driveshaft were pulled, I removed the center console and the relevant shifter parts, covering the shifter mounting area well so no debris could fall into the open cavity. I searched for a used transmission jack to assist in removing the T5, but couldn’t find any deals worth getting. Refusing to pay $300+ for a tool that would see minimal use at best, I pulled the T5 with my floor jack and a helper – he pulled on the jack while I kept the trans balanced. Jack was sitting on a furniture dolly from Harbor Freight, that helped a lot. Will be thinking through installation process as fighting gravity will make it a bit tougher.


I've used this HF furniture dolly for about everything EXCEPT moving furniture. Sure comes in handy when you need it.


The serpentine front accessories came off, along with the radiator and electric coolant fans. Only casualty was the original AC lines that run between compressor, condenser, and dryer. All other parts were new when I upgraded to a Sanden compressor last year. I had planned to just bungee cord the compressor out of the way, keeping the system closed. However, when moving the lines, I heard a snap then a slow “hisssssss.” New manifold parts going in. Should have bought new to begin with as the replacement was only $80.

Engine pulling was a big day. My father came over to watch and lend a hand. Once far easier than I had anticipated (this is my first engine pull). Only the motor mount bolts were holding it to the frame, so after removing those and pulling the distributor to allow extra room in the back, the hoist gently pulled it free of the engine bay. Was a greasy, oily mess!

Less comfortable than it looks.



Father lending a hand to keep the engine from crashing into the firewall. I'd wanted to install my load leveler, but there wasn't enough room along the back side of the head to install the bracket.

The big hulk sitting on its stand. My neighbor opted to buy it for a couple hundred bucks to turn into a coffee table. I'm excited to see how it turns out.

Following engine and trans removal, a much emptier engine bay. More to take out with harness and fuel lines.


The electrical harness in this car had been a butchered-up mess before I bought it. I’d worked on areas of it to clean up cut wires over the past couple years, but getting the whole mess out of the car felt great. I had thought it would be a piece of cake to slip the large connector that hooks up the ECM through the hole in the passenger fender. No matter how I tried, there was no way I was getting that connector through that passageway. So, went the reverse and pulled the entire harness out the other way, ending in the bulkhead connector. I had to remove its retaining clip to squeeze it through the opening, but it worked.


A jumbled, cut-up mess. Glad it is out of the car.


The final items removed were the fuel lines. The carb’d lines exit on the passenger side, while TPI exit on the driver side. I had earlier cleaned and painted the fuel lines from the 88 parts car, along with all the retaining clips. While working on the TPI EVAP line, I discovered it had rusted through and was completely clogged in spots, so starting thinking up a solution. The lines came out easily in one assembly once everything was removed from the engine bay and under the car. Just unbolted the clips and separated the brake line, then fed them out of the car. Had to be just like how the factory installed them.


Taking the fuel lines out as a single assembly was very easy. On the parts car, I had to remove them individually as the transmission was blocking pulling the EVAP line out - which ended up being a rusted hunk anyway.

With that, Phase 1 was complete!

 

I knew this part was going to be the pits. I had earlier replaced the two-piece rear main seal when I did the oil pan gasket. New valve cover gaskets were also installed shortly after my purchase to try and minimize/eliminate leaks. Regardless, the bellhousing and top of the transmission were an oily, gooey mess. Adding to the amount of work was my using water-based cleaners like Dawn dish soap and Simple Green to try and cut through the sludge. I have a good understanding of chemistry, and why I didn’t immediately grab the two cans of engine degreaser I have on the shelf, I’ll never know. So those jobs took forever, especially the transmission with its multiple little areas for sludge to hide. After being reminded on this site about solvent-based cleaning for oil, everything went quicker!


Inside of the bellhousing. A nice, thick coating of sludge has blackened everything.

Closeup around the clutch fork pivot pin. Just nasty.

The outside isn't much better. The line of black shows how far I'd been able to reach in the past to get it cleaned and wiped down.

Took a lot longer than it should have because I was using the wrong cleaning material.

Similar story on the transmission. Not as oil-covered, but lots of little nooks and crannies to get the gunk out of.
Armed with my cans of degreaser, I went with a vengeance on the engine bay. Some light spraying and things just wiped clean. Went through a couple rolls of paper towels, but end results were very satisfying. I had always planned to paint the top of the K-member, as I had painted what I could reach when I had replaced the front suspension a couple years ago. After seeing all the open space, I also decided to paint the firewall and fenders/frame rails where I could mask off. A color-matched spray can cost $35 and ended up being a very close match. After seeing the final results, I’m very glad I went that route.


Engine bay and K-member degreased and deep cleaned, getting ready for paint.

Tinfoil works great on the brake lines, then lots of newspaper for overspray.


On to the yellow. Drew the line at completely stripping the engine bay and messing with suspension and alignment, so did some masking off of areas in the rear.

Three coats of the color matched paint and it turned out pretty nice.
Lots of other small part cleaning and painting, like the torque arm bushing housing. The original, rubber bushing was cracking, so I ordered a replacement polyurethane one. I would have preferred another rubber bushing as this car isn’t driven hard, but it appears to me that those parts are no longer produced.

 

This section is where the brain juices had to get flowing. It has been really great having a complete car that I pulled all the parts from, plus the pictures I took of the strip-down process over two years ago. The main parts of converting are the wiring harness and fuel lines. I started with the fuel lines, which would have been lots easier if I’d had a good EVAP line. I decided the easiest route would be to use the EVAP line from the 85 and bend it over the trans tunnel to exit on the passenger side. Using a hand tube bender, I eyeballed where to bend the line by following the route of the carb return line. It took some trial and error, especially in the area where it comes up the frame rail and tucks under the AC box, but I think final results are good. It is a bit shorter than the original line, so I ran a section of 5/16” fuel line that will end at the EVAP canister.


This area was tough, especially laying under the car trying to figure out where and in which direction to place the bends. Took a bit of finessing, but ended up ok. I wish the line had been a bit longer to it didn't exit underneath the evaporator box.


I had earlier gone through the entire harness and simplified it as I am going from MAF to MAP and using a 16197427 ECM to control the setup. Even with all my pre-work, though, it still took over a week of consistently working on the harness to get it ready and installed. I’d tagged all the connectors when removing it from the parts car and kept most of the routing the same. One area I changed was to route the electrical fan wiring along the inside fender as opposed to along the passenger frame rail. I’d mounted the power wire for my amplifier in that fashion and knew that would also work for the fans.

Converting to the ‘7427 required some extra work. All the MAF wiring and relays were removed and a MAP sensor was wired in. My 85, with its computer-controlled carb, had a MAP sensor mounted next to the fuel relay and a corresponding vacuum line, so I kept that location and wired it in. Had to do lots of de-pinning from the ‘7730 to ‘7427 connectors. To help make sense of the process, I’d created several tables that detailed each pin, where it started and ended, and wire color. Then double- and triple-checked my work.

A quirk I stumbled across is that the punch-out in the kick panel between an 85 carb and 88 FI car are different widths. Not sure if that is due to a change in the fueling system or year. The 88 FI plug is 5mm wider than the original, so it required a bit of clearance for it to fit. Not the easiest place to cut, I used a combination angle grinder, sawzall, and dremel. I think the dremel rotating shaft got a bit too close to the yellow speaker wire, so will be splicing in a new section there as well.

5mm difference in width between original and "new" ECM plugs.

For looming material, I’m trying the Alex Tech woven mesh loom. It looked nicer in the pictures than the original, corrugated style loom and seems to give a cleaner, more finished look. During hookup, I’m going to keep an eye on any areas that get close to the exhaust and make sure it stays far enough away.

The FI harness, finally all wrapped and ready for installation in the car. It went in easier than it came out, possibly due to the different loom material?


I’ve gone through most of a roll of TESA tape, and still have a few other harnesses to swap from the original loom to the mesh. Last part of Phase 3 that I have to tackle is mounting and wiring in a wideband oxygen sensor. Planning to place it in the pipe that a PO welded in place of the catalytic converter, then route into the cabin through either another hole in the kick panel (not ideal because of the plug size), or slice into the grommet for either the cruise or HVAC.

This is where the project stands as of today. Now need to get back to the garage and play around some more!

 

Spent a few hours the other day figuring out the routing for the wideband sensor cable and placement. I opted to install the sensor where the catalytic originally was, before PO welded in a straight pipe. Really, REALLY wish I had taken it to an exhaust shop to at least make the system able to be separated into two sections. Will do that as soon as the car is up and running again.

A friend down the street came up with his welder and did a nice job sealing it in. Looked closely and didn't see any pinholes, so hit it with some black High-Temp paint to hopefully keep rust at bay.

Routed the cable along the frame rail, than up to the HVAC grommet. Once I pulled the grommet out a bit, was able to slice it and remove a small chunk so the cable would sit in there snugly and the grommet would seal back up. A little bit of silicone covered up the slit.

Wideband sensor coming up from the frame rail. Pinned in place with the EVAP hard line.

 

One item that I knew I'd have to address, and eventually did, was the cruise control harness. My original cruise servo was mounted on the frame rail where the battery is now located, following changing to the serpentine belt setup from the 88. The location that the 88 used was on the driver fender, which meant I had to shorten the cruise harness and brake dump line by about 12". Not a big operation after drilling and mounting the servo bracket in the new spot, but had to find a good ground location as I didn't want to run wires all the way back to the head, and the original grounds were at the radiator core support, meaning I'd have some ugly wires strung too far. Found a good location in the fuel line clamp at the driver frame rail.

New location for the cruise servo. Wish I'd drilled the holes before repainting the fender!


Completed cruise control mounting

Now needing to tackle something unexpected... The heater diverter valve requires a vacuum line that my 85 HVAC controls did not have. From what I see in the service manual, the 85 had no such diverter, coolant just ran through the heater core all the time. At least by 88, GM installed the heater diverter to keep coolant out of the heater core unless warmer temps were called for on the controls. Would help make AC blow more efficient, I'd guess. I have the controls and the lines, but need to splice into my existing vacuum lines as I'm not removing the dash and heater box to install the complete harness. Drawing the line there! If I can splice in the lines for the input to the diverter, then I can run the output line through the same grommet that I just used for the wideband sensor.

More to follow...

 

Nice progress!

 

Some progress since my last update. Mainly, engine is in, along with the engine bay harness. Some hiccups along the way, like at least a day spent hooking up the heater diverter valve that I mentioned in the previous post. Might as well start there!

The 85 model year for TPI did not come with a heater diverter valve, based upon diagrams of the cooling system I saw in my factory service manual. The metal pipe that runs from the heater core to the radiator is just a straight shot, no inlet port from the diverter valve. Since the return pipe that I have is from a later model car, I had to either cap it or figure out how to make the thing work. Living in South Central Texas, it gets hot. The AC I repaired early on works great, so I figure keeping hot coolant out of the heater core during summer months will be a bonus. I learned lots about the heating system during this project!

The diverter valve is vacuum controlled by a separate vacuum switch in the HVAC control unit. There is a slot stamped into the metal plate that turns the switch on and off, when it is properly aligned. More on that later.

1988 HVAC control on the left, 85 on the right. Note the slot in the metal plate and the vacuum switch with a post that rides in that groove. That is the on/off switch for the diverter valve.

Next challenge I faced was how to splice into the vacuum lines to route vacuum to the diverter switch, then run a new line into the engine bay to control the valve. That turned into a fiasco, as those colored lines do not seem to be "splice-able" like regular vacuum lines with regular connectors. Tiny diameter when I cut a spare one open. I purchased a length of 3mm silicone vacuum line to run into the engine bay to the diverter valve, plus a whole lot of fittings. Ended up finding that the best way to splice was just to shove each end into a small piece of the 3mm line. Just the right size and holds vacuum really well. Never ended up taking a picture of the vacuum line repair, but the 3mm stuff worked great.


Circled is the incoming vacuum source that splits off to the diverter valve switch and the vent control switch. My 85 didn't have that T, so I needed to splice it into my existing lines.

In order to route the line into the engine bay, I fed the silicone line into the cabin from the same grommet I slit earlier for the wideband oxygen sensor. Carved out a little more material so it would sit flush on the firewall, then sealed it again with a dab of silicone sealant. Fed the line up along the coolant hoses to the valve, all works well.

After running all the vacuum lines, I wanted to troubleshoot the system. Could get everything to work once or twice, but then the vacuum would not turn on and off properly to the valve. After lots of checking, I found that there was enough slop in the stamped plate that the small pin that turns on and off the diverter switch would slip out, rendering it completely ineffective. Not sure if this was poor manufacturing from GM or just wear and tear on the unit. I chalk it up to a bit of both, as that plate should have been resting in a channel to keep it firmly in position. I scratched my head for awhile, then realized there was an easy solution. Above the plate was a hole that wasn't tapped, but located in a perfect spot to mount a hold-down bracket. I keep a couple small sheets of ABS plastic in different thicknesses, for random stuff like this. Cut off a small strip and gave it a 90-degree bend. Filed it down to where it provides a positive lock for the plate to keep it firmly in position so the diverter switch pin cannot fall out. Easy fix, took lots longer to come up with the solution than to make the part!

Small piece of ABS to hold the vent control plate in place, thereby preventing the diverter pin from falling out of the slot.

Once this small project was all done, I realized I spent WAY too much time thinking about and working on that valve!

 

Took a week off to do a father-son fly-out, drive home trip. Didn't want to get the engine in and have it perched there until I returned, so that was waiting for me when we returned.

What we picked up - a 2004 Mercury Marauder. Just ate up the 1,500 miles from Chicago to Austin. Great car!

With the engine harness hanging in place and the diverter valve done, I felt that all the stuff that would be difficult to access with the engine in place was taken care of. Dropping the engine in was really easy. Pulled it off the stand and lowered onto a tire so I could mount the flywheel and clutch. Then it was a matter of just lifting it into the engine bay and putting in the motor mount bolts.

Thought I was being very clever to wrap up the excess chain to keep it out of the way. Ended up biting my in the butt as there was not enough slack to allow the engine to rotate enough to get into position when going in over the fender. Managed to finally loosen it enough to get it properly aligned. Glad I'm not being judged based on speed.

Sitting in its new home. Valve covers were off to keep them from getting chewed up by the chain as the engine was going in.

Shot of the clutch install. I had initially thought the bellhousing would be attached to the transmission, then bolted to the block, so I created to guide posted to help with the install. I then realized there was no way to install the clutch fork and throwout bearing using this method, so followed by mounting the bellhousing.

 

Two things happened after I installed the engine. First, I installed the oil pressure sensor on the top of the engine block, where it was originally located. Then, I needed to remove the sensor so I could change the routing of the wiring harness and bolt in the ground leads to the cylinder head. Somehow, lying on my back and looking up, I attempted to loosen the sensor by accidentally tightening the ever-loving snot out of it. Had my righty-tighty, lefty-loosey backwards and stripped the brass housing. That ended up being a blessing in disguise, though, because I then found out that later model F-gens (90 and up?) used a single oil pressure sensor and switch that mounted above the oil filter. I had the oil switch in place, but no sensor. Found that part still available on Amazon, so picked that up and routed the sensor wire that goes to the gauge in the dash down to the appropriate location. I was fortunate enough to have the correct plug from the wiring harness that came with my engine, so snipped it off and spliced in the sensor line. Now, the rear of the engine is much cleaner and easier to route wires without that huge can in place.

Three-wire oil pressure sensor and switch used on later model thirdgens.

Once the bellhousing was mounted, I figured I would bolt in my starter. This is where the second issue arose. I should have seen it coming, but it never crossed my mind. The flywheel dust cover original to my car is for a 2-piece rear main seal. Now that I have the larger, one-piece RMS, the dust cover couldn't slide into position. Took a few trips between the workbench and the car to get enough material cut away while still keeping its integrity.

Original dust cover marked with my best guess for material to be removed to fit the later engine block.

Tools of the trade

Had to remove a bit more on the sides then my initial sharpie drawing called for, but it ended up fitting in there nicely.

 

We are now caught up to my current state. On my road trip from Chicago to Austin, I'd picked up a transmission jack adapter for the low, low price of $20. Thinking it would be easier to install the exhaust before the transmission, I crawled under the car to slide it into place. Suffice to say, it did not go well. The situation has been greatly aggravated by an earlier owner who installed larger diameter exhaust (I think), removed the cat, and welded the whole assembly together. I have one solid piece from the y-pipe all the way to the tailpipes exiting the car at the rear. Doing anything with my exhaust bites the big one. The one piece of prep I missed, and frankly never even considered, prior to starting the project was to take the car to an exhaust shop and have them separate the pieces and mount a hanger. This is on the top of my to-do list once the car is up and running again!

After wrestling the pipe into position, I found that my clearance around the oil pan is WAY off. While building the engine, I took lots of measurements of the one-piece pan and compared it as best I could to the original that was still mounted in the car.

My calibrated, tape-measure drawing and optimistic conclusion

The primary concern I had was that it would clear the K-member, which it does without difficulty. However, as the engine sits now, there isn't enough room for the Y-pipe to cross under the pan. Yesterday was spent attempting to "massage" the pipe to allow enough clearance. Got closer, but still not able to bolt the pipe to the manifolds.

This picture was taken early in the massaging process. I proceeded to use practically every hammer in the tool box to try and gain the clearance.
Here is where the welded exhaust really got me. I'm under the car trying to swing a hammer - was a struggle to get any force in the swing and have it hit where I wanted. After several hours of working at it, I developed a really bad attitude and called it a day. My plan of attack is to now install the transmission and see if the area opens up more once the engine is fully in place with the transmission cross member provided the third mounting point. If the exhaust still does not slide into place, I'll take a sawzall to it around where it should have bolted to the catalytic converter, drag the front section out from under the car, and proceed to beat the **** out of it until it fits. I want to get this combination up and running before considering swapping in headers, but this might be an accelerant.

If anybody reading this has any ideas, I'd love to hear. Taking today off to allow the hands and shoulders some rest.

 

The carnage-inducing beating on the exhaust was done for the day, although the pipe ended up even more abused than the above picture. I decided before getting more barbaric on the pipe to install the transmission and see if that would help with clearance. Plus my hands, forearms and shoulders were killing me from swinging every size of hammer in my toolbox under the car. After resting a day, I slid the trans under the car and found out I'd wasted my time (and didn't do my exhaust any good) by trying to fit the exhaust before getting the transmission mounted. The engine had been tilted so far back on the front motor mounts that the tailshaft of the transmission was only about 8" off the ground once installed. Once jacked into place and the transmission crossmember was bolted in, there was plenty of room for the crossover pipe to clear the pan and mount to the manifolds. Unfortunately, my rapacious beating on the pipe tweaked it out of alignment a bit, so took some wrestling to get into place.

Moral of the store to anyone following along - Install the transmission FIRST before exhaust. I'm an idiot.

Here are a few pics of the transmission setup I'd hoped to use. I'd picked up a transmission jack adapter plate that fit perfectly into an older Craftsman floor jack that I'd just received from my uncle. Unfortunately, even with the car jacked up high in the air with the QuickJacks, then braced front and rear on the passenger side with jack stands, I just couldn't slide the transmission on the jack under the car. Tried tilting it forward so I could then pivot under the car, but no luck.\

My well-intentioned, but ultimately unsuccessful use of a trans jack adapter

Whole setup was just too tall. Next idea was to slide the trans under the car on its own, then dead-lift it the small amount onto the jack was it was positioned in the trans tunnel. That worked, but the engine was tilted so far down that there was no way to match the angle with the jack. So, put it in the way I took it out. Used my HF floor jack under the car and laid the trans on top of it, then slowly jacked it up and tilted it by hand at the same time (had helper working the jack handle at the rear of the car). I'd previously modified two 12mm x 100mm bolts from Home Depot to act as installation guides - thank goodness for that! Once I got the transmission on the guide bolts, it more or less slid into place with some jiggling around. About 1/4" away from the bellhousing, I could no longer push it the trans in by hand, although it wiggled around fine. I turned each bolt about 1/4" turn in sequence about three times, then I was able to push it the rest of the way in by hand. One big piece off the floor! Then spent a couple of hours figuring out how to get my exhaust bolted back up after tweaking it a bit out of alignment. Had to drop the entire thing, then start with the manifolds and work my way back. Once the car is running, before I do anything that requires dropping the exhaust, I'll be taking it to a shop to have it separated and a hanger installed. It just sucks working on it this way!

Yesterday, slid in the driveshaft and the torque arm. My rubber torque arm bushing had torn, so I had the polyurethane version ready to install. Would have preferred keeping it rubber to minimize vibrations, but there are none to be had. I knew getting the clamshells clamped and installing the top bolt was going to be a bear, but it really kicked my butt. Turned out to be another two-person job, after I wrestled with it on my own for too long. To ease the install, I lifted up the rear axle to minimize the torque arm angle and try and get the bolt located as close to the trans hole as possible. Then, while I was under the car holding the torque arm down, my father came in from the cabin and could get the bolt tightened from above. Without the shifter and trans tunnel cover removed, I'm not sure how you could get that bolt in. Watched a klowny youtube video where he had a stud on the inner bracket that allowed a nut to be started, then clamp down the outer bracket. With the T5, there was not extra stud like that. Oh well, it's done!

This bolt caused some words and phrases to be shouted that I'm hoping the neighbors didn't hear. Don't see how it could be installed accept from the top.

 

It’s easier to install the bolt into the bracket with no torque arm then slide the torque arm into the bushing before sliding the torque arm onto the axle and bolting it down there.

 

Good to know! I hope to never need to take it out again!

 

Fuel system finished and tested today. No leaks (yeah!!!) and fuel pressure set to about 47psi. Had a minor anxiety attach when I first powered up the fuel pump from the relay with my Power Probe (great tool, by the way). Nothing happened. Then realized that I hadn't hooked the negative battery terminal to the engine block. After that, pump fired right up. Huge sigh of relief, because the idea of dropping the tank to replace a bad pump did not sound good at all.

 

After installing the fuel rail and confirming the system holds pressure and doesn't leak, I started to think heavily about the condition of my fuel injectors. The Bosch III units came as part of a complete TPI setup I purchased a few years ago and been sitting on, waiting for the right time to install. Amazon sells a simple kit to run carb cleaner thru the injectors - some YouTube videos show how to make your own, but the Amazon one includes both a fitting for the injector and the plug for electrical connection. Cost was $14 with tax, so I went that route.

To increase the nerd-factor, I used an Arduino and relay to turn the injector on for 0.25 seconds and off for 0.50 seconds. This let me get by with a single set of hands. Otherwise, you need one set to hold the injector to the fitting and can, another set to trigger the injector by pulsing your 12V source.



A modified computer power supply, an Arduino and relay to pulse the Bosch III injectors

All pulsed well and shot cleaner thru in similar, fan patterns. Not a replacement for a professional cleaning service, but I'm going to give these a shot in the car.

 

The next day, I went around and hooked up the front accessories. Alternator - no problem. Power steering pump - no problem. Sanden AC compressor ... Crap. The Sanden is an inch or so longer than the original R4 compressor. The additional length wasn't a problem on my previous valve covers because they had a slight slope to each edge that gave the compressor enough room. My new, center bolt valve covers are pretty much straight up and down, and all of a sudden I had a problem.

Sanden compressor bolt hitting the valve cover with still about a half inch before getting to the mounting hole.

I spent an hour digging through TGO for any ideas on ways to get the compressor mounted. It is much better than the R4 style and worked great, no way was I going back to the old one. There was a post from several years back with someone showing how he made his brackets to mount the Sanden to the original housing. Looking at that, I finally realized that if I flipped the Dirty Dingo mounting brackets, it would rotate the compressor enough to hopefully get it out of the way. Success! I lost the lower mounting bolt, but the compressor feels very solid in its revised mount.

Dirty Dingo brackets flipped from original mounting style. Rotated the compressor enough to clear the valve cover.

Due to the new location of the compressor, I needed a longer belt. Gates K061000 did the trick, about 20mm longer than the belt I'd used previously.

 

After mounting the radiator and routing the plug wires, the next step was to install the runners, plenum and throttle body. I'd purchased this set from a 91 Vette three or four years ago and had polished all the upper parts. Was my first time tackling a polishing job and I had a really good time. Took FOREVER, I'd estimate 40+ hours between sanding, wet sanding, and polishing. The parts had been sitting in the attic, now was the time to bring them down and get them on the car!

Runners went on easily enough, although I found the lower bolts to be impossible without the allen key with a rounded head to allow getting in at an angle. Been a long time since I'd had to buy hand tools as I've got tool chests full of about everything you could need for basic tools. Could different styles of the 6mm hex wrench, but no go without the special head. Bought a complete set on Amazon and the bolts went right in with the correct tool. Have ended up using only the 6mm wrench quite a bit on the TPI setup. Fits easily into tight spots.


This was my victory picture after getting the upper intake assembled.

With the upper intake on, I was checking out the throttle cable and connection to the TB when I realized I was in trouble. The TB from the Vette has a different provision for the throttle cable than the F-Body. If you look closely at the picture above, you can barely see the place where the cable routes, and then terminates in a barrel-style design. Wasn't going to work with my throttle cable. C'mon GM - why?!?!

Pulled down the TB from my 88 parts car as I knew it had the correct hookup provisions. Was reading through my TPI book and saw that earlier style TB's weren't compatible with later plenums, which I have. Having both of them in my hands, I could see the difference was the idle air passages on the back.

91 TB on the left, 88 on the right. The difference is the cut-out portion in the 91.

My modified 88 TB with opened up idle air passages. Used a cutoff wheel for vertical guide cuts and a die grinder with carbide bit to remove the material. Really glad this work can't be seen once installed!

Now with it able to function properly, I had to make it look a lot better. Out came the palm sander, wet and dry sandpaper and the polishing wheels..

Unpolished 88 TB on the left, polished 91 on the right. Have to make the one look like the other.

After a couple days of working on the TB, including the air passage mods and polishing, it came out like this. Turned out better than the 91 that I'd done a few years ago. Skills are improving!

 

Last couple days have been buttoning up all the little things, installing the factory cold air intake and putting filling coolant and other fluids. I'm using the MAF sensor to connect the intake pieces, but it is non-functional. Checking on a small coolant leak from the metal line from the heater core to the radiator. Hoping the last twist of the hose clamp will seal it off.

Hooked up my laptop to the 16197427 ECM and was able to get limited readings when I turned on the key. Nice to know the car is coming to life! I discovered the fuel pump relay wasn't working as it would click on and off but the fuel pump wouldn't power up. Fortunately had another in a nearby box, so after swapping it out it primed the system perfectly. Waiting for the last couple of items to arrive from Amazon tomorrow to finish the vacuum lines on the throttle body. I'm capping the line into the TB from the passenger valve cover as I'm using a traditional style breather. Also waiting on 1/4" basic fuel line to run from the EVAP cannister to the TB. Once that is in place, I will be hooking up my DIY smoke machine to check for any vacuum leaks. Then... I think it's ready to fire? Not sure, will need to check through everything again.


Current state of engine. Two vacuum lines to hook up, then start testing everything before firing it up.

 

The later TB would work, just need a 89-92 F-body throttle cable.

 

Good to know. Fortunately, I had the 88 throttle cable to mate with the 88 TB.

 

what a journey. im just finishing up my engine and will then start something similar. im excited to see this fire up.

 

Thanks! I'm waiting anxiously for two grommets to arrive so I can properly install the PCV system. Pulled the breather and found the correct, molded hose from Hawks Motorsports. Grommets coming from Amazon and are ones for thicker, aluminum valve covers. Seems to take FOREVER when you are needing the parts!

 

Been too long since I've updated the goings on out in the garage. Engine was running (poorly), lots of diagnosis, new parts, and a cylinder head removal. Will pick up where I left off, best as memory - and pictures - serve.

Engine surging was a constant problem, will get into the findings there later. I could get the car to idle with RPMs fluctuating between 800-1200 rhythmically. While checking vacuum, timing, etc, started hearing some louder tapping under the driver valve cover. Then, the tapping became much louder, like pieces were banging around.I pulled the valve cover and found the #1 exhaust rocker arm was extremely loose on the shaft. All valves had been adjusted to 1/2 past zero valve lash on the engine stand, so my locking nut had come loose. I decided to do a valve adjustment with the engine running and modified a valve cover I pulled from the scrap yard.

Two rows of holes because I found out I'd had the valve cover pointing in the wrong direction when I'd eyeballed it on the engine. Nothing a little duct tape can't fix.

The PVC tube is a great size to fit in the hole and around the rocker nut, keeping oil from squirting out.

The continual culprit, #1 exhaust nut. Could watch it spin off while I was adjusting the intake side.
After setting the #1 exhaust to 1/2 past zero lash, I started working on the intake valve. While getting it adjusted, the tapping started again and increasing in volume. I was able to look down the #1 exhaust hole and SEE the nut turn counter clockwise! So much for locking.

*** Here, a Public Service Announcement about the quality of today's parts ***
I'm certain this will come as no shock to most of you, but the quality of the parts we are buying today are absolute garbage. I'm much more likely to use an old, original, OEM part than purchase a new replacement because of my concern that the new stuff - even branded AC Delco items - is just junk. I had bought all new rocker arms, studs, lock nuts, and pivot ***** from Rock Auto, advertised as OEM quality. Think the brand was Engine Tech, which sends parts to major engine rebuilders. Right out the box, one of the sixteen nuts is a total fail. Ugh.
*** End of PSA ***

Fortunately, I'd save the box with all the valve train parts I'd taken off the engine prior to getting it machined. Used one of the lock nuts and that problem was solved. For now... Further heartache to follow.

 

Valves were adjusted, engine still stumbling along, and my fuel pressure would drop fairly quickly when the car was shut off - even with both the main and return lines pinched. Decided enough was enough and ordered a rebuilt set of injectors from South Bay. That way, I was eliminating a variable of the unknown Bosch III injectors that came with my TPI setup. Aside from the fun of removing the TPI plenum and runners, was an easy swap.


The spacer SFI mounts to the bottom of the injector makes installation of the fuel rail really easy. I had o-rings on the first set and they worked fine, but the rail took some wiggling to get mounted in place. With their space, easy-peasy.

 

New injectors and the fuel pressure was nicely stabilized, with no leakdown when the fuel lines were pinched off. Another potential problem solved.

Engine was still surging with a terrible idle (common theme). I was trying lots of different settings in the fuel and spark map with very little improvement. I'd done enough cold cranking and rough starts that I could tell some gas had gotten into the oil. Drained the oil and ordered more Lucas 30W break-in oil. While waiting, I figured I pull the plugs and check them out. All showed running VERY rich, which wasn't a shock given the AFR I was reading with my wideband. When I got to #4, something new...

Electrode and tip touching can't be a good thing!

Here is where the fun began. My first thought, like an idiot, is that the piston must have come in contact with the electrode, bending it up. So, I grab my inspection camera and check out the bore and piston. It looks ok, but I can't quite see the bottom edge, so I put on a right angle attachment to the camera and check again. All looks good, so feeling vindicated, I pull out the camera... and leave the attachment in the cylinder. Holy buckets of crap.

The attachment is metal, so I make a magnet/wire combo and with a friend's help, attempt to fish it out. We were making a bit of progress until I pulled the end of the wire off and find the magnet is no longer attached. Now, no choice but to pull the head.

My two little culprits. The snaky lines on the piston is from our hunting around with the magnet and wire.

One item I'd noticed while removing the head is that one of the valves ha da little gunk on the stem, rest were spotless. I was also trying to figure out how I could have had some kind of ignition/detonation even occur that would screw up the spark plug. Got to inspecting my lifters (the same ones I'd rebuilt at the very beginning of the project). I was able to compress #4 exhaust by hand with a pushrod, while all the others were very firm. As this was the cylinder that had the issue, I decided it was time to do what I should have done in the beginning - install new lifters.


Picture on box shows flat tappets, but these are roller lifters.

Amazon delivered the lifters and gaskets in a couple of days. Everything went together smoothly.

 

Couple of fun things I did on this assembly. My timing cover has the tab welded on at 12 o'clock. Trying to set timing is an absolute nightmare, requiring me to remove the intake elbow, climb up on the front core support, and try and peer around the fuel lines and TB heater bypass hose to see the tab, all while holding the timing gun and turning the distributor. Since everything was off, I pulled the balancer and installed an aluminum timing tab at the 2 o'clock position. Took some modification of the mounting piece, but very happy with the end result.

The driver front accessory bracket has a tab that protrudes and was interfering with getting the tab mounted into place.

Piece marked for clearancing. Shame, as it is a nice polished piece. At least in my serpentine TPI application, the nice edge is totally hidden.

And thank goodness it is hidden! Now looking like it has been attacked by a family of wolverines, it at least will now fit nicely into the location.

Good view showing the interference with the accessory bracket and the amount of material that had to be removed.

Final result, MUCH easier to view and adjust base timing. Just visible on the left side is the white mark on the balancer. I made sure engine was at 0 TDC before locating the timing tape. If I could do it again, I'd move the tape a little further down from the pointer. However, that adhesive is not coming off!

I did a lot of researching here on TGO and couldn't find a definitive answer on where the factory timing tab is located on TPI cars with the serpentine setup. If anyone has it at 12 o'clock like me, I highly recommend this change. Took some effort to pull and replace balance, plus hog out the material to get it to fit, but worth the effort, in my opinion.

Also while the engine was apart, I decided to make my own water neck gasket. I'd purchased a sheet of gasket material earlier to make one for the idle air controller, something that does not seem to be available on its own. Since I now have a lifetime supply of gasket material, saved a few bucks and cut out my own, using the previous, practically brand-new gasket as a template.

Fel-Pro, eat your heart out!

 

New gaskets and lifters, engine reassembled and fired up. It starts idling GREAT! I'm pulling about 16 inches of vacuum and it sounds pretty good. Not perfect, but better than anything before. Feeling like King of the Hill, I'm watching my datalogs and see the wideband readings are off on the far left column and the check engine light is on. Low MAP voltage. That is when I realize I'd hooked up the vacuum line but never plugged the harness into the MAP sensor.

Shut engine off, disconnect battery to clear code, and fish the plug from behind the engine. Fire engine up with big expectations and.... SURGE, SURGE, SURGE. WTF!!!

On the upside, I feel like I might be getting close on the heels of the culprit that has been hounding me since I first fired up the engine. I figure I'll swap the MAP in the car for a known good one on my TBI Corvette. Wait... The plug is different. I start digging into anything I can find about different MAP sensors, failure symptoms, etc. That is when I discover that my 85 - originally a VIN G car with a computer-controlled carb, had two sensors - one that sensed manifold air pressure, and one that apparently sensed barometric pressure. Guess what, they look exactly alike!

Correct MAP sensor is mounted to the plenum, the wrong barometric sensor is in my hand.

Not realizing the plug difference, I'd pulled the one from the original harness when I modified the MAF system on my 88 parts car to run Speed Density (MAP). Oops, egg on my face! After splicing in the correct plug and sensor, the engine fired up and idled BEAUTIFULLY! Amazing what happens when the ECM gets the correct vacuum signal!

 

Now that engine was idling and I had made some tweaks to my fuel and timing maps to get it to idle around a 14.0 AFR, I wanted to give it some time at higher RPMs to get the rings to seat. After getting the engine to operating temperature, I start opening the throttle blades, bringing it to 2000-2500 RPM. A minute or so later, I start hearing that familiar tapping sound, then louder, louder, LOUDER. Back off it off to idle and shut down the engine, knowing what to look for. Sound was again coming from the driver side, so pull that cover. This time, not one but TWO valves are loose. The #7 exhaust is causing the loud taps as it is floating around, and the #1 intake is loose - just not as bad as #7.

These valves are driving me to drink!

Please refer to PSA above while I proceed to bang my head against the wall. Deciding enough is enough, I order the ARP studs and locking nuts. Feels like overkill for my very mild build, but I have confidence these parts should tighten those damn rocker arms in place. If not, I'm at a loss!


Heads stripped back to how I received them from the machine shop.

Built this organizer when I stripped the engine for rebuild. Didn't think I'd get to use it again so soon. Will keep the rocker studs in the attic, but throwing the nuts in the trash.

 

While waiting for the ARP parts to arrive, I decided to upgrade my narrow band oxygen sensor to a heated version. I'm running factory manifolds, so I don't think this is really necessary. However, I was getting wonky readings from the sensor, probably from the overly rich conditions it had been abused to while I was getting the engine to the point of running better. Plus, I had earlier purchased a Bosch 13077 sensor, identical to the one I installed on my TBI Vette. However, I had not corresponding harness connector. Usually I grab that from the junk yard, but given the fuel cost to get there and back, plus the entrance fee to the yard, it was cheaper for me to buy a 10-pack of connectors and roll my own.

Never built a weather pack connector from scratch, went well. I don't have the correct crimping tool, so I used the crimpers I have and soldered the wires into the terminals as a backup. I now have a lifetime supply of three-prong connectors to go with my gasket material!


Now just need to splice this into the car over the next couple of days.

Have a Happy 4th of July!

 

Thanks for the update. Quite the trials.

 

I console myself with knowing this is part of the education process. Otherwise, I'd probably be going bat-***t crazy!

First of the ARP parts arrived today, so installed and torqued them down. With the heat here in Texas, I was ready to head inside after this quick job!

 

Now have the lock nuts installed, they sure look nice! Valves were set at 1/2 turn past zero lash, per the instructions that came with the Comp Cams roller lifters and following the instructions in the factory service manual for setting the valves at #1 TDC and #6 TDC.


After getting the valve covers reinstalled and everything else buttoned up, started the engine up and let it get to operating temperature. Sounded good, so brought it up to 2000 RPM to seat the rings, running it there for around 10-15 minutes. While it was at this high idle, started hearing louder tapping again, this time from the passenger side. Feeling fairly disgusted, turned the engine off and went inside to cool down - emotionally and literally. Middle of a heat wave here in Texas!

This morning, pulled both valve covers again - getting really good at it! The #2 exhaust lock nut was starting to come loose, so I'm thinking there is an error in how I was tightening everything down. I would bring the outer nut almost to the 1/2 mark, then get the inner nut tight. Finally, I'd turn both the wrench and the hex key the last 1/16 to bring everything to a full 1/2 turn past zero lash. Going to do some web research on the proper procedure, see if I missed something. I'd appreciate any thoughts here as well.

#2 Exhaust - the offending culprit. As can be seen in the picture, the set screw is further down in the hole than the one on the left. Outer nut was only finger tight.


Another item happening during higher idle was the occasional miss. Not sure if that is valve related or ignition - possibly one of the spark plug boots not fully seated? I'm pulling all the plugs to check them out and help in turning the engine over to inspect all the valves.

Good times!

 

Adjust them while running. Take the valve covers off. Idle only and be as expedient as possible.
loosen a rocker till you hear tapping/clacking. You'll for sure hear the difference, it'll sound distinctly different. Then tighten till the clacking just goes away. No further. Lock that nut temporarily, move to the next rocker. Do all 16. Again, quickly, to avoid more oil mess than you need. It normally isn't bad when at slow idle speed. You can build cardboard shields too if so inclined, I never have.
now after you made each one clack and tightened them back just to stop the clack, shut it off.
With it not running, set your preload suggested by the lifter manufacturer. You can do the preload while running but it affects the running usually(because the engine is filling the lifters so you're fighting that)

 

did you do any detailed posts on removing wires from the bulkhead?

 

Not sure I understand the question. When I changed the car over to TPI, I removed the C100 (pulling from memory, the main bulkhead connector) of the carburetor car and installed the bulkhead from the fuel injector harness. I took a bunch of pictures from the project in 2021 and 2022, so if there is something that will help, let me know.

 

thats right it was a carb car. I built a fairly healthy 383 with a first tpi unit that im installing into my 91 firebird that was a 305 tbi car. so im having to remove several of the wires from the bulhead that ran things that the new holley hp will now run on its own harness. the wiring is scary.

 

Separating the two halves of the plug was a challenge. GM filled the cavities with potting material which made it tough to get them apart. I liked the wiring part of the project, done it a few times on different cars. Best of luck!

 

So you left us hanging. Is there a conclusion to this? Did you ever get it running right?

 

Oops! It is running good. My only complaint is a slight dun-dun-dun sound that varies with engine speed. Very faint and I've been all over it with a stethoscope but can't locate it. Been like that for the past three years or so. I've made my peace with it and just run it and enjoy it. Performance is just what I wanted. Snappier than stock with the mild cam and heads while being totally comfortable on the cheap pump gas.

I've put maybe 800-1000 miles on it, just short fun trips around the area with the kids. The T-tops stay off from March until November. Makes me grin driving it, remembering college days when I drove my first yellow TA. Guess that makes it all worthwhile.