Just had mechanic swap 88 Formula L98 into 87 GTA which originally had LB9. He said he had to do some splicing of some of the wiring harness which came w/ the L98.

This wasnt the biggest issue though. He said this engine sits further forward than the LB9 which now causes the intake plumbing not to hook up\ properly.

What Should I do.

 

A. Start working on your own stuff.

or

B. Get a new mechanic. Regular shop mechanics generally do not do swaps like this. they are good at replacing an LB9 for an LB9

 

L98 should mount exactly the same as an LB9 since they are both small block Chevy engines and the motor mounts are in the same place.

 

Hey Mongoose

I thought the same thing. Have you ever heard of something like this happening before?

This is killing me becasue the earliest that I can get to it to see it for myself is Tuesday.

 

I've heard some nightmare stories before but not one of a small block sitting further forward of the one it's replacing. Did they mention anything about transmission or driveshaft issues? That would lead me to think they screwed something up. As for the wiring there "may" have been a few things that needed to be changed but it shouldn't have been much (really shouldn't have been any since you're going from '87 to '88). Who did you take the car to?

 

A place called Get-N-Gear. They are off of Old Charlotte Hwy in Bakers a stones throw from intersection of Rocky River Rd and Old Charlotte Hwy.

They are suppose to be transmission experts and ex Nascar tranny and general mechanics. They had several engines lined up to be swapped out along the time mine was so I thought they knew what was going on.

I checked this out pretty good before I took my car over there talking to everyone on this site. No one ever mentioned that this would be a possiblity. I cant see how this could happen being that the engines are virtualy idential.

I am hoping that they didnt screw up my car!

Ill wait until Tues before I finish passing judgement when I see stuff with my own eyes.

No mention of driveshaft or tranny stuff. Only splicing wires and engine further forward. Also need a 88 L98 PROM. Where can I find a good deal on one.

Can the L98 run on the LB9 chip? I ve heard that becasue of the diff injector size that it would make the L98 run lean.

 

I've never had any dealings with them as I do all my work myself. As for the chip it should run just not like it should. You can check the classifieds here and see if someone has one to sell or check with TPIParts.com, they have real GM PROMS for reasonable prices. The only thing I can think of (if the engine is sitting on the motor mounts correctly) is that the intake duct on those year cars isn't exactly straight. Even when they were brand new the piece that came from the TB and made a 90 degree turn to the MAF sensor had a slight bend back further towards the engine's passenger side. Then from the MAF sensor it connected normally to the air filter housing. The appearance of this first piece of ducting made it look like something wasn't installed right but in fact it was. IF this is the case then it's pretty much normal. Let me know what you find out Tuesday.

 

I was thinking along those same lines about that Filter plumbing. Id noticed the odd alignment becasue I had to spray statrer fluid in the intake to start it up everytime I drove it then turned it off and then tried to crank it while engine is still warm. When I placed that flex rubber piece back on it was always some rustling to make it fit decently.

Maybe they didnt get a good mental picture of it before removing it and becasue its not going back on easy they think something is wrong. How hard is it to change a PROM chip. I may just try to get this one issue solved get my car outta there and deal w/ the rest myself.

 

Chip swap is easy. Drop the passenger side trim panel under the dash and look for a large wiring bundle on the far right side. Reach up and you should feel the computer, just pull it out of it's bracket and then down. There should be 2 screws holding the small cover on, just remove them and you should see the chip. There should be a locking tab at each end of the chip, just push down gently and the chip should pop out. Install is simply reverse of this.

 

Front to rear engine spacing is "adjusted" by rear tranny mount. On my car I needed it moved forward to clear valve cover/wiper motor gained 3/4 inch.

Loosen frame/cross member bolts, holes are oversized, pry forward/back retighten.

 

OK, Just got back and looked at the car. The engine is where its suppose to be. The problem is the MAF plumbing. That box on the 87 TPI that runs at a right angle off of the intake will not fit between the air cond compressor and the radiator.

Remember on the 88 and up the alternator and air cond compressor are on opposite sides than the 85-87 TPI.

Can I just find the 88 TPI rubber boot and be done with it. The MAF will fit but the black box will not.

Other suggestions?

Also he is saying the car will not crank. He is saying its becasue the MAF is not plugged in. Is this true? Will the puter prohibit it from cranking while the MAF is not pluged in?

Give me all of your thoughts please.

 

With a little research I see that a cold air kit would take care of the problem.

 

88 L98








87 LB9

Notice the alternator location and the air cond compressor loaction

 

I only way I have seen a maf unplugged keeping a car from cranking, is after the battery is dead. If the default table is off, the car will crank till the battery is dead but not start,

 

Yep, you need the intake plumbing from an 88. You can usually find those pieces on ebay or here for pretty darn cheap. As for the car not cranking, that has zero to do with the MAF. It may not idle so well without the maf.

 

Won't crank or won't start? There's a big difference. Did YOU actually try to start it when you were there and if so exactly what did the car do? Dash lights come on? Fuel pump prime? Starter solenoid click?

 

Was talking with TPI Parts about this not cranking situation. They said it is a possiblity if I used the 88 harness on a 87 car that the position of some of the prongs in the plug that conncets to the computer may be diff. In other words maybe the wire that send info from the starter is in position 6 on the 88 and its in position 4 on the 87. I assume no one else has had this problem?

 

The more I read this, the more it sounds like such a waste, why didnt you just use everything from your lb9? and just swap blocks? I mean, this sounds like such a waste for a minimal gain of HP.

 

My LB9 was knocking and I eventually will rebuild it and put it back in car when I restore car back to original one day. I could have rebuilt the LB9 right away but w/ a little research and chating w/ fellow third geners the swap seemed like a simple exercise. In hindsight looks like I chose the wrong people to help me out with this swap.

 

Mongoose I am going back Monday and I will be specific about cranking vs starting. I see your point about the diff. I was so pissed after seeing the car and realizing that nothing was wrong with the engine placement just intake plumbing that I didnt even invesigate why the car wouldnt start.

If the car will crank and run I will likely take this car somewhere else and have it finished. I need to work I own my own business and just got a big contract and need to see to it that I make my customer happy in the 1st months of this deal or else Id do this myself. As I research things I can see its not that hard to do a swap I just dont have time right now and Im ready to drive my car.

 

Since this appears to be a wiring issue now with the differences from '87 and '88 I'd suggest locating a detailed wiring diagram for both years and locating a good '87 harness to start over with. Are they still working to get the car running or just letting it sit?

 

Car is just sitting. I actually like it better that way becasue at this point I dont trust them. Ill have the weekend to decide whatI want to do next week.

 

Hey Mongoose:

You are right on the mark w/ the harness suggestion. Was refered to a harness guru by

 

Hey Mongoose:

You are right on the mark w/ the harness suggestion. Was refered to a harness guru by a fellow third gener and he said he use to work w/ these well Ill just paste the quote in here

"Sorry to hear of you troubles. Your best bet is to use the 87 harness, but send it to someone who can modify it for the TPI engine. That makes the wiring plug and play. I used to do this work, but now only build brand new fuel injection harnesses.

I can guarantee that you can not plug a 1988 harness into a 1987 car. Details can be found in the service manuals. I apologize that I do not have the available time to go through all of the details.

I think TPI Parts was offering a harness rework service. You could also try http://www.enginewiring.com."

Well at least I have some sort of resolution. I dont think I am gonna leave this car up there just for them to run up a big bill. I have no confidence that they can figure out how to get my car going. Ill just have to find someone that I can trust and hopefully do more homework before making that move.

 

R&R of the harness isn't a terribly difficult job, just time consuming if you don't know where everything goes. It wouldn't surprise me if Angel at TPIParts was able to both provide the harness and conversion as well. Once the harness is taken care of you should be able to swap it out in a day if you take your time.

 

If you're swapping a 305 TPI out for a 350 TPI, I would have swapped front engine accessories and recalibrated the prom. It would be that easy.

No harness changes, no hassles, very straight forward.

 

S10Wildside

With the 88 engine in now and having the harness issue that I am having what would be best? Change the harness or the accessories off the 87 LB9?

 

I can hardly believe that they decided to make harness changes rather than installing the 87 front accessories on the 88 engine. Put the 87 TPI harness back in the car, put the 87 front accessories on the 88 engine, and the problem should be solved. Unless they already cut into your original harness. Be sure to load a 350 TPI calibration into the prom.

In this way...

• no alternator relocation
• no A/C compressor relocation
• no wiring changes (at all)
• no intake air duct changes