Sequential Injection on a Gen I Motor! - DIY PROM - Third Generation F-Body Message Boards

69 Ghost · 03-24-2006, 10:45 PM

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....

http://www.pacificp.com/forum/viewto...r=asc&start=80

scuzz · 03-25-2006, 08:50 AM

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.

Kaiser · 03-26-2006, 08:07 AM

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?

scuzz · 03-26-2006, 09:34 AM

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

JP84Z430HP · 03-28-2006, 12:13 AM

Quote:

Originally Posted by Kaiser

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.

Kaiser · 03-29-2006, 06:36 PM

Thanks for the info.

dimented24x7 · 03-31-2006, 01:14 AM

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.

Kaiser · 03-31-2006, 08:31 AM

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...

dimented24x7 · 03-31-2006, 09:14 AM

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.

69 Ghost · 03-31-2006, 10:44 AM

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.

Kaiser · 03-31-2006, 11:27 AM

http://www.hptuners.com/help/

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).

Besides, the HPT folks have also given back to the hobby - for example here:
Corvette Forum - How a 3d Table works

That work was all done for free... which brings us back to the topic as it relates to TGO.

69 Ghost · 03-31-2006, 01:44 PM

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.

scuzz · 04-01-2006, 10:03 AM

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?

JP84Z430HP · 04-04-2006, 11:19 PM

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.

S10Wildside · 05-09-2006, 09:32 PM

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.

Grumpy · 05-09-2006, 10:59 PM

Quote:

Originally Posted by JP84Z430HP

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.

S10Wildside · 05-10-2006, 04:34 AM

Quote:

Originally Posted by scuzz

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.

S10Wildside · 05-13-2006, 07:47 PM

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.

Looking forward to Ron installing this.

APACHE JOHN · 06-14-2006, 03:08 PM

Any new news on this? I'm very interested.

S10Wildside · 06-14-2006, 03:32 PM

Quote:

Originally Posted by APACHE JOHN

Any new news on this? I'm very interested.

Me, too.

scuzz · 06-14-2006, 04:56 PM

I'm trying to get my heads finished at the port shop. Just waiting to put on heads and install engine. Maybe soon.

scuzz · 06-15-2006, 09:17 AM

By the way, S10Wildside did a great job on building the harness for this project. It is mostly hidden and well built. Thanks S10WIldside.
Ron

scuzz · 06-30-2006, 07:41 PM

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

Grumpy · 07-02-2006, 12:18 PM

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..

Just something to think about/ investigate.

scuzz · 07-02-2006, 06:08 PM

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.

dimented24x7 · 07-03-2006, 12:48 PM

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

man that sucks. I really liked TC alot.

jwscab · 07-03-2006, 01:33 PM

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.

are you sure about the TC/JET stuff? I know the OBDII stuff was not on tunercat.com, but at Monodax Homepage - TunerCat OBDII Scanner and Data Logger - MXScan Info-. that would surely suck as TC kicked a$$, but I question JET. maybe it's been that way for awhile?

scuzz · 07-03-2006, 05:30 PM

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.