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First of all thanks Ron for the persistence in finding this link.
All I think a number of people here would like a sequential fired motor and 4l60 control in one shot. The 96+ Vortec truck setups were overlooked due to the intake configurations which used CPI or also known as SCPI in which stands for Sequential Central Port Injection. The newer distributor setup along with the crankposition sensor in timing cover was the key. I don't know all the details but the truck links are converting to marine intakes. Point is this setup can be used with any Gen I intake from stock GM parts. Enough said it will cost $$ due to OBDII but I think it would be worthwhile. Now shoot holes in it! Link page shows how to convert the harness to regular injectors....
I'm in contact with the guy that started the thread and I've already gotten some info, and he is saving the next setup for me if I want it.
I'm going to do some searching still before starting to try the conversion.
That's a pretty interesting project. Does anyone know off-hand what the IAC control device looks like
on an L-31 throttle body - i.e. will the L-31 PCM control a TPI IAC motor, without modifying either?
I'm also trying to find out the same. I've been searching everything I can find to get an answer. I've not found an answer yet.
If anyone knows, please chime in.
Thanks,
Ron
That's a pretty interesting project. Does anyone know off-hand what the IAC control device looks like
on an L-31 throttle body - i.e. will the L-31 PCM control a TPI IAC motor, without modifying either?
Works exactly like the TPI IAC. As far as I know, pretty much any GM IAC works the same. Exceptions would be the Cadillac Idle motor, and I believe the drive-by-wire stuff doesn't have an IAC, but I'd have to verify that. I just took a peep at the LT1 TB I have in the garage, and compared it to the L31 TB, and the IAC is the same. They're just a simple stepper motor. Electrically, they're pretty much the same. The main differences in IAC's is the pintle deisgn, and of course the mounting, and the electrical connector.
What about the PCM side of things? Supposedly those are based on the 68332's, which little is known about as far as PCMs go, and the PCM tuning programs seem to offer little tuning capabilites considering the large chunk of money that you have to part ways with in order to get a copy, or (groan) have them flash it for you.
From what I've found on the 93-95 PCMs, there is a ton of stuff in there that has never seen the light of day on any car tuning forum. On top of that, even knowing what it all does doesnt make it look like itll be any less excruciating to properly tune and set up. Just blindly using one looks like it could be a hassle if you cant make changes.
It would definatly be sweet to use one of these, but theres not much available yet.
Looking at p.12 of the original reference, the authors mention using either TunerCat or
HPTuners software on '96-99 L-31 PCM's. As these are all OBD2 I'm not aware of any DIY
editing yet available.
Is there something wrong with the quality of the commercial packages? I haven't looked
at them personally, but was under the impression they were pretty complete...
Most of those packages are $500 or more for one vehicle. They offer a good general tuning package from the overviews they give, but they only seem to touch on the base parameters in the computers. There is, of course, alot of stuff in the first generation of PCMs (I could probably spend a week typing and still not cover it all), so I can only imagine the later ones are even more complex. As long as you dont have to really touch some of the advanced items, youd probably be fine.
There are a number of tuning packages for OBDII's. Tunercat has come out with one that is not locked to the PCM but it may still not be on the website. Craig has the roadrunner stuff that I am sure could be adapted. The cost associated with OBDII also has to do with the interface cable that costs about $250.
For a complete scanner/editor/interface/flash package it doesn't seem outlandishly
expensive to me.
Over the years I've easily spent that much on chips/programmers/adapters/
cables/UV eraser(old school)/TC software/loggers/spare ECMs. Come to think
about it, the original copy of Diacom+ I bought 15 years ago was $500 by itself(!).
And that stuff is awfully primitive compared to the new-generation PCM capabilities.
According to these guys, the new computers & editors are suitable to handle
GM-supported SCCA road-race efforts (read down a few posts): Corvette Forum - Some of our C6 World Challenge race car photos
AFAIK stock GM PCM's run the C5 , C6 and CTSV cars in SCCA WC - they seemed to work
well enough to win the series last year(Caddy).
The only complaint about HPTuners and the others are that they are locked to one computer just like the cra**y handhelds. I would still buy TC and Autotap to not be locked down as opposed to these guys. For real time tuning the Roadrunner is the way to go but it costs even more. I have found that I cannot drive and emulate to tune at the same time so until Craig and Mansur come up with a OBDII system for programming other than the Roadrunner I would still go TC and Autotap.
I finally got a chance to go to shop and take off Throttle Body from Vortec intake. I cleaned it up and have enclosed a shot of the TPS and IAC. If they are about the same as TPI or LT1 stuff, it looks like the connector could just be repinned.
Am I on the right track?
Hey guys, I'm in the process of making a template to build new OBDII TPI harnesses. I should have more details and pics by next week. Ron has been a big help supplying parts for a prototype harness (OBDII RamJet 350). From a wiring standpoint I see no real issues. Converting a used Vortec harness to a MPFI setup (like TPI or RamJet) is a little messy because the harness is not routed behind the heads like a TPI harness. I have some pictures...they'll be online when I get a break from harness work.
You probably won't even have to repin! Well, the IAC phase may be off, but that's function of the ECM/PCM being used, not really the IAC itself.
I've used that series of IAC on a C3 ecm without a hitch.
There seems to be allot more different sytles of pintles with the later ones thou.
And some variances in the hole the pintle seats into.
I finally got a chance to go to shop and take off Throttle Body from Vortec intake. I cleaned it up and have enclosed a shot of the TPS and IAC. If they are about the same as TPI or LT1 stuff, it looks like the connector could just be repinned.
Am I on the right track?
I had no problems getting a RamJet 350 running on my test stand with the 1227730 ECM. The RamJet uses the same IAC as the Vortec and LT1/LS1. Not sure if the part number is the same. I sold the engine to a guy in Tennessee and never heard from him again. Street and Performance has been offering a RamJet 350 harness with the 1227730 ECM, so it sounds like it's a proven design.
So if the newer IAC works with the 1227730, it sounds safe to assume that the older IAC will work with the OBDII PCM.
Because of the way the Vortec harness is routed in the truck's engine compartment, I built a new harness rather than rework the old one.
The truck harness is routed over the left valve cover, rather than behind the engine. The harness does loop around and head down to the transmission, but creates over 1 foot of bulk that does not allow for a very clean install.
Here's the almost completed OBDII Ram Jet harness.
I finally got my heads back from port shop, and went to change them and found out that I had one cylinder wet for a couple years while engine was sitting in 58 vette at body shop. Had to tear down and sleave one cylinder and rebuild this week. I fnally got engine back together and heads on today. I took a couple pictures of the timing cover and L31 stuff that goes on front of engine. When I get back Monday, I'll get Ramjet intake on the engine, bolt up trans and drop drivetrain in the 41 pickup I chose to use for project. I took a 350 TBI/4L60E with a 93 harness/ecm out in order to go with this project. I may be sorry I did in the long run, but it's still sitting in shop floor in case this deal goes south.
I test fit my L31 dist to the Ramjet setup yesterday, and found out that I'm going to have to do a lot of work on fuel rails to clear funky dist cap on the vortec. It's flat with 4 plug wires coming out each side that hit both fuel rails where fuel goes in and out. I'll deal with that Monday, a friend that can tig weld is going to help me then. I don't think the TPI setup will cause the same problem, but I'll check it out and get pictures also then.
The engine I'm using came out of a L31 98 truck, but when I put it in the vette, I took all the L31 stuff off and threw it away, ( how many times have I done that?). So I had to visit my buddie's junk yard and round it all back up.
When you change the timing cover to the truck plastic one, you'll have to pull the two line-up dowel pins in block for lining up metal cover. The plastic cover has them attached to cover. The timing wheel goes on after timing gear, and is lined up with notch to crank key.
I asked several of my mechanic friends if used covers were okay and they all assured me that as long as they were clean, and in tact, and a new balancer seal was in, it was okay.
When you get your cover and timing wheel, don't forget to get mounting bolts also. The plastic cover uses a totally different bolt.
I'll report more progress next week.
Pictures of cover and wheel attached.
Thanks,
Ron
Before you go too far, you might fully investigate the PCM to see if you can edit what you'd expect to be able to.
Some of the new stuff doesn't use AE, not being able to tune that parameter, makes some new stuff really ackward to work with. You might to be able to do a work around with the cal..
The main reason I've taken so long to get started is some of the newness with OBDII to me. I am just now starting to understand some of the OBDI TPI stuff.
I learned that Tunercat II is the only program that supports 96-99 Vorted PCMs. Their sales and support was taken over by Jet a month or two ago, and I refused to buy from them, so it took about a month for me to find an individual with the original TCII that I could purchase and xfer ownership. I have also found the owner of www.wait4me.com that is going to help me get started by sending me a startup def file that I can build from. He tunes loads of these trucks for people. If I can see what he's done, that will help me get started. I have learned to read pcm and re-flash, and how to take out egr, cannister, and some other basic stuff already.
EFILive datalog program is probably what I'm going to start my datalog files with as soon as I can get the engine running and driveable.
It seems that there are several tuners already into the truck pcm tuning. I have found info on fullsizechevy.com, performanceTrucks.net, and a few of the LS?/LT? boards have members that are tuning truck stuff.
The support is nothing like thirdgen. You guys always have an answer and are more than willing to help anyone that has a problem.
I hope I can get this project up and running and maybe it will help others that want to try the newer stuff and still use all their old gen 1 stuff.
I plan on installing engine/trans tomorrow, and try to start wiring.
I'm going to post more pictures of fuel rail mods and dist tomorrow.
The map sensor is totally different looking on the Vortec and Ramjet manifold, but I guess it can be just fitted to our harness. I believe they work the same.
If I get in too deep, I'll just have to learn how to get out.
Thats cool to see youve nearly got it together. Im keen to see how it ultimatly works.
Im surprised that they only use a four tooth reluctor on the crank. Im not familiar with the newer stuff but is there a cam sensor as well? Maybe they just correct for it timing wise like they did in the previous PCMs.
I too agree with getting familiar with the PCM before trying to run the car. They pack ALOT of stuff into these things.
Quote:
I learned that Tunercat II is the only program that supports 96-99 Vorted PCMs. Their sales and support was taken over by Jet a month or two ago
the 4 pole crank sensor generates the pulse-per-cylinder reference. The distributor has a cam sensor that generates a square wave; basically, high for half the cylinders, and low for the other half. I'm guessing the code looks for the rising or falling edge (or both) and running frequency, and compares with the crank reference pulse to get misfire information.
I tried to order a copy of Tunercat II from John at tunercat.com 6 or 8 weeks ago after talking to him a couple times about it. He informed me that he had turned it over to Jet to market, but his original customers would be serviced by him, so I found an individual that had one of the original copies and bought it and John xfered ownership for me. TCII has unlimited use and Jet limits you to two pcm's and upped the price a couple hundred or so.
I got the engine and trans down in my 41 pickup today. I am going to attack fuel lines and intake tomorrow. Then start installing the harness that S10Wildside made up for me.
I'll post what I run into as I go.
I plan on not using egr, cannister purge, and the third oxygen sensor, since it works past cat, which I will not use either.
Georgia has non-existant laws for cars from about 68 down.
Here's pics of the vortec dist in a TPI intake, which gives great clearance. The Ramjet fuel rails had to be cut, shortened, and re-tigged, and re-routed on right side, but dist works great now.
It would be nice to have someone else helping. I'm having a tough time doing this project by myself. I know no one that does any OBDII stuff, and don't have any sources, except the truck and LSX sites to read other posts.
Please bear with me if you are interested in this thread, I'm trying to hold down my job, and work on a couple different projects at the same time, plus have a life.
There's a 58 vette TPI/miniramIII/700R4 and a 67 Firebird conv TPI/700R4 also in the works. I go from one to the other, depending on the day. I'm looking at 60 and want all my cars done before I retire so I can enjoy them.
Forgot pictures. CRS.
I have that Intake. it's been sitting on the shelf for two years now. I don't like GM's fuel lines at all. I was thinking of a connecting tube in the rear. Running the supply to the passenger side front and the regulator and return off the drivers side front. 3.8L GM engines have a similar set-up. With a little work I think it could fabbed to connect to the factory TPI lines. The reason for the regulator being on the driver side is the throttle linkage is on the passenger side. Of course you already knew that.
I tried reversing the rails and use the tubular crossover in rear and fittings in front, but the regulator hit throttle body flange on intake, and crossover hit dist. Shortening worked great if you have access to tig and milling machine to make downspout on right side. I think I have enough room now.
With the TPI intake, no problem. I'm trying to attach to this post. I hope it works.TPIleft.jpg
Ron you are breaking ground here. If I get some time I can look at the def files and probably help you out with the egr, etc. I still think that you will be getting the best of both worlds and OBDII only stands for more $$$$. The LS1 guys are past that and tuning away. It is too bad TC went the Jet route but you did good getting a previously purchased setup off of Ebay. Like I said before it is as good as gold if you are going to be doing this for a long time. What you are seeing on the Thirdgen site limited exposure since there are a number of people moving towards the new stuff.
I'm also about to finish up a new build based on the 99 Vortec setup. Running StealthRam with 30#/hr SVO and flat-tops with 64cc Edelbrock E-Tec 200 heads. Put some spacers in to give more clearance at the front, so some additional plenum volume. Looks pretty sick really. Eagle 4340 H-beam forged bottom end, JE pistons, internal balance. Planning to run A/T with Vigilante 3200 in a 99 Tahoe 2-door.
Planning to use TunerCat OBD2Tuner to tune with, although I'll probably go ahead and fit the PCM with a Roadrunner to see how the RT goes in that regard. Looking forward to some good datalogging via the Monodax stuff, should have that in hand later today if all goes well.
I'm probably about 3 weeks out, need to spec a cam right at the moment based on the ported head flow results. Looked pretty good, got over 275 on the intake, around 210 at the exhaust. Valve seat pressure is only 125# though, so there's some shimming to do first.
I'm also about to finish up a new build based on the 99 Vortec setup. Running StealthRam with 30#/hr SVO and flat-tops with 64cc Edelbrock E-Tec 200 heads. Put some spacers in to give more clearance at the front, so some additional plenum volume. Looks pretty sick really. Eagle 4340 H-beam forged bottom end, JE pistons, internal balance. Planning to run A/T with Vigilante 3200 in a 99 Tahoe 2-door.
Planning to use TunerCat OBD2Tuner to tune with, although I'll probably go ahead and fit the PCM with a Roadrunner to see how the RT goes in that regard. Looking forward to some good datalogging via the Monodax stuff, should have that in hand later today if all goes well.
I'm probably about 3 weeks out, need to spec a cam right at the moment based on the ported head flow results. Looked pretty good, got over 275 on the intake, around 210 at the exhaust. Valve seat pressure is only 125# though, so there's some shimming to do first.
I'm waiting to see what cam you come up with.....
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Scuzz I have a Ram-Jet intake. What I meant was fabbing the rails and lines to hook up to the factory TPI supply hoses in the front. I know it was kinda hard to understand what I meant.
Last edited by APACHE JOHN; 07-07-2006 at 05:53 PM.
Reason: Automerged Doublepost
I'm waiting to see what cam you come up with.....
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Scuzz I have a Ram-Jet intake. What I meant was fabbing the rails and lines to hook up to the factory TPI supply hoses in the front. I know it was kinda hard to understand what I meant.
As I usually start from scratch with streetrod stuff, that slipped by me. Sorry about that. I have never owned a complete thirdgen car, just engines and trans in 5 different streetrod cars/trucks. They are a great package in anything, especially since I found TGO.
I really appreciate all the help and info I've gained from you guys.
Ron
I just found this post on DFI and ECM board. It is the post about 96-99 Vortec dist/timing cover.
It seems that Fast355 has already gotten the Vortec stuff working on a 305 TPI system w/4L60E trans. That's great to know that it will work.
I just got my harness back from S10Wildside and am ready to start back on project.
He modified harness to run a 1220041 PCM from a 2001-2002 Express van which ran a L31 engine, and the PCM is the same that trucks, vettes, and fbody cars ran those years.
I'll try to get some info posted back soon as I threw my back out a few weeks ago, and I'm limited to what I can do again.
S10Wildside has decided to go with the same deal also, and he's using a TPI intake also.
Check out his post in the TPI section: http://www.thirdgen.org/techboard/tp...-opinions.html (TPI OBDII - Thoughts/Opinions)
The work he has done for me is great!
I just got my harness back from S10Wildside and am ready to start back on project.
He modified harness to run a 1220041 PCM from a 2001-2002 Express van which ran a L31 engine, and the PCM is the same that trucks, vettes, and fbody cars ran those years.
I'll try to get some info posted back soon as I threw my back out a few weeks ago, and I'm limited to what I can do again.
S10Wildside has decided to go with the same deal also, and he's using a TPI intake also.
Check out his post in the TPI section: http://www.thirdgen.org/techboard/tp...-opinions.html (TPI OBDII - Thoughts/Opinions)
The work he has done for me is great!
Thanks,
Ron
The TPI motor is more of a prep for installing the 12200411 PCM in my S-10. Looking forward to using the newer electronics and a 4L80E.
So here's my problems:
- Crab-type distributor hits the fuel rails where the wires come out on the sides. Do they make a vertical-wire version?
- If I was to transplant the pick-up stuff from the stock distributor over to a MSD-standard-type, think I could get away with that? The 'stock' pickup is a half-crescent magnetic 3-wire pickup.
- Reluctor wheel at the front of the crank hits the double roller. If I shim it out, I'll have to cut back the balancer. Isn't there a 'specialized' reluctor available for this sort of application?
As it stands, I'm planning to spend some quality time on the metal lathe and mill building the following:
- Hub 'adapter' to replace the existing MSD paddle-wheel with a step-up 'platform' with set screws that will secure the 'stock' style distributor-mounted cam position reluctor.
- Special 'stepped reluctor' for the crank snout that will relocate the outer edge of the reluctor earlier in the diameter to escape the roller chain clearance.
Any ideas? Maybe something available from crank builders (Callies, etc) on that reluctor? Maybe an 'alternate' part source from a different year/model application that has some stuff in common distributor-wise on that cam reluctor without having a crab-style cap?
Got this motor just itching to go in! Last few details (as usual!).
I shortened and angled the rear of both rails so the dist would not hit. See above picts.
I believe there is a roller for the vortec block. Look for roller for 96-99 L31 engine.
That's all I got. Maybe someone else can chime in.
Ron
I took a piece of billet alum and drilled it to match up with fuel hole in right side rail after I had shortened it and cut at an angle so I could run the fuel outlet down and screw in an AN fitting in it. Then just TIG it up good and check for leaks. The right side was worst. I could only shorten right side a small amount and then angle cut back of FPR bracket and TIG it up.
Both side mods took me about a couple hours and a good friend about 30 minuites to TIG back up.
I looked large for different dist cap with no luck. The original L31 had a big ugly breather in that area that covered everything, so there was no room.
Ron
instead of a bunch of welding and fabricating, cant you just plug the hole in the back of the fuel rail after trimming for clearance, and come in from the bottom, or side of the rail? nothing says its gotta enter the rail at the back. You could even enter the rail in the middle on a stealtram, and run the lines through the space between the front and back runners.
the reluctor I suppose would get a little problematic. If machining another one with a different profile works, thats the best way to get both things you are looking for (reluctor and double roller). You might have another product to sell!
So here's my problems:
- Crab-type distributor hits the fuel rails where the wires come out on the sides. Do they make a vertical-wire version?
- If I was to transplant the pick-up stuff from the stock distributor over to a MSD-standard-type, think I could get away with that? The 'stock' pickup is a half-crescent magnetic 3-wire pickup.
- Reluctor wheel at the front of the crank hits the double roller. If I shim it out, I'll have to cut back the balancer. Isn't there a 'specialized' reluctor available for this sort of application?
As it stands, I'm planning to spend some quality time on the metal lathe and mill building the following:
- Hub 'adapter' to replace the existing MSD paddle-wheel with a step-up 'platform' with set screws that will secure the 'stock' style distributor-mounted cam position reluctor.
- Special 'stepped reluctor' for the crank snout that will relocate the outer edge of the reluctor earlier in the diameter to escape the roller chain clearance.
Any ideas? Maybe something available from crank builders (Callies, etc) on that reluctor? Maybe an 'alternate' part source from a different year/model application that has some stuff in common distributor-wise on that cam reluctor without having a crab-style cap?
Got this motor just itching to go in! Last few details (as usual!).
Craig,
I don't know of a vertical-wire type for the vortec engines, although there might have been one for the big block motorhome or something.
Which brings me to the reluctor, the 350 Vortec was available in alot of HD applications as well. I would go into your local GM HD parts division and have them take a look at what is available.
Reluctor wheel at the front of the crank hits the double roller. If I shim it out, I'll have to cut back the balancer. Isn't there a 'specialized' reluctor available for this sort of application?
My S-10 is using a Cloyes double roller timing chain. I'm also very interested in a solution to this problem.
- Special 'stepped reluctor' for the crank snout that will relocate the outer edge of the reluctor earlier in the diameter to escape the roller chain clearance.
FWIW - when I did this on my L98 the crank reluctor wheel OD runs approx 0.005"
clearance(gap) from the end of the crank sensor. The sensor body is approx 0.75"
diameter.
If I had made a reluctor wheel with a smaller OD (to clear the double roller
sprocket teeth) the sensor would need to be pushed further into the engine.
It seems to me the crank sprocket teeth then would hit the sensor; or have
added extra signals to the (hall effect) pickup.
Not sure if that's what you were thinking, but you may want to check your clearances.
, but theres not much available yet. 
