Guys,

I'm cross posting this here from Camaroz28.com because there is much more traffic here. I had forgotten I was a registered member here until just this morning. I'm desperate for suggestions and help as this car at one point was my pride and joy and spent many hours pounding the local SCCA.

ANY help would be very much appreciated!

__________________________________________________ _____

http://www.camaroz28.com/forums/lt1-...weight-880826/

Pics of what was inside the PCM found here:
http://s1215.photobucket.com/user/pr...?sort=3&page=1


If you guys would rather me just copy/paste everything here so there is no need for linking, I will gladly do so. I realize it's a bit much to ask you to click link after link just to read the story and offer help. Let me know!


Thanks,
John

 

Here are the basics of the story - Car is a 1994 M6.

Missed 2nd gear, spun the car north of 7k and she stalled immediately. Found a bad opti.

Swapped opti with Delphi unit and at the same time went ahead and did the mezeire electric water pump as well.

Car hasn't been reliable since. I wired the W/P directly to key on power (I know this is looked down upon but I rarely drive the car so figured it wouldn't hurt) in the underhood fuse box. Not sure, but think I used the ABS relay spot? I can't remember.

Originally thought the opti pigtail was bad so I replaced that. A few short trips around the block later the car was still intermittently dieing on me. It was at the point I found jiggling the main harness over the heater box caused odd things to happen - then I found one of the harnesses on the PCM had broken tabs and was loose. I have since made a bracket and zip-tied the harness in place.

Opti is a Delphi with total of maybe 600 miles on it. Been randomly dieing since around 80-100 miles.

ICM is new and spaced off the head.

Coil is MSD - checks out on ohm check within spec.

MAF is clean.

Coolant temp sensors are both new Delphi.

Cleaned a bunch of grounds. Have yet to clean/replace battery negative ground but it's on the list to do ASAP.

Fuel pressure key on is 42, at idle is 36. When car dies fuel pressure remains constant.

Oil pressure cold startup is around 40, when hot it's around 20. It comes up with throttle slightly.

Recently replaced ignition switch and problem still remains.

Opened PCM and found what is linked above (pics).

FYI - the issue is absolutely random while sitting in my driveway. Cold, hot, doesn't matter. Sometimes it will fire up and run for 2+ hours with no issues. Other times it'll fire up and run for 5 minutes and die. Sometimes when it dies it will restart immediately, other times it will just crank and/or stumble but not start. Sometimes 20 minutes later it will start, sometimes it won't.

 

Looks like moisture found its way into the pcm. Have you tried swapping it out with a friends pcm? That would take 15 minutes.

 

I have not. Mostly because I failed to keep a lot of friends through the years who were a big part of the local camaro/firebird scene.

I also read somewhere that any replacement PCM would need to be programmed w/ the VIN and tune to work correctly in my car, which I have no idea about how that works.

Have been considering buying a remanufactured PCM though.

 

Appears to have a PCMforless sticker? Surely they could handle programming a new or different pcm for you. I think it's safe to assume that one is **** canned based on the pictures.

 

I'm in touch via email with them now and going to hope they can assist in getting me another PCM and/or tuning a remanufactured PCM for me.

 

Here's my concern if I must buy a reman PCM -

http://www.napaprolink.com/detail.as...+5999999+26209

Part: NEC XTP78051F
Product Line: NAPA Reman. Computers

Application Information: 1994 Chevrolet Camaro
Engines : 5.7 L 350 CID V8
Comments: Vehicle Specific Flash Programming Required On Or Off The Vehicle. Accurate VIN And Mileage Are Required. Additional Vehicle Specific On-Car Programming Must Be Performed After Installation to Prevent Drivability And Starting Issues;Knock Module Must Be Removed From Original PCM And Installed In Replacement PCM
Per Car Qty.: 1

 

I get conflicting advice from friends saying I should just be able to plug it in and drive it.... but NAPA's website says the above.

 

They dont come with the module

The problem is that most of the pcm come with no programming, some do, If you have no way to flash a program into one, then you have to take it to the dealer, problem is, the dealer cannot bench flash, Has to be in the car, of course if its in the car, it wont run, You can pick up any PCM with that service number and it will run. PM me if you want, I have OBDI PCM's and can flash it to your specs..

,

 

I think I understood that clearly.

I'll send you a PM now, thanks!

 

Any used ecu will work. I have swapped ecus in my car. even from Obd2 to Obd1. Nothing special. Only change is the knock sensor. Unless you had a tuned ecu them you will need to retune the used one. Otherwise drop in and go.

 

Go on ebay and search for "1994 Camaro PCM". Buy one listed as "programmed for your VIN". Buy it. Send them your VIN. When you get it, send BOTH PCMs (the bad one & the new one) to PCM for less.

They keep all files they make for PCMs. They should be able to find the original and put it into the new one.

 

I'm actually waiting to hear back from PCMforless on whether or not if I provide the VIN or even the current/bad PCM, if they will have record of the tune in it.

I'm not going to get out of this cheap, either way. It's looking like $300+ no matter how I go.

I need to spend an hour or two soon and troubleshoot the opti for the off chance that something is amuck before I go tossing $300 PCM at it just to see it continue doing the same.

 

It's been brought to my attention that it very well may be a bad battery cable that is causing this issue.

I'm going to swap both of them.

If it's not fixed my plan is to dig around the coil wiring and make sure it's all 100%, then troubleshoot the opti, and if it's good I'll then spend the $ for a new PCM.

 

Vin Programming is easy. With the tuner software you can change the vin in the ecu. I bought a 95 Buick Roadmaster ecu and installed it with out touching it. The car fired right up. I have also installed a buddies ecu while troubleshooting. That one was out of a 95z28.

 

That just adds more curiosity. If they'll run w/ any used PCM, what's the need to program in the VIN?

Both tuner's I've consulted said it's required.

 

This PCM is shot. Before trying to fix other stuff that you *think* it might be, get the PCM straightened out first.

 

"Albertson" on the PCM For Less sticker will tell them what settings they put into it. When you get a replacement PCM, send them both to PCM For Less.

 

You mean to tell me it's not supposed to have parmesan cheese sprinkled on the circuit boards like that? I've been looking for some 12-volt marinara sauce and spaghetti wires to go with it and have had no luck.

LOL

I actually heard from an old friend last night that he may have a '94 M6 PCM for me. Even better, it's tuned for CAI, EGR/Cat delete! He's double checking today and with any luck, I'll be plugging it in this evening!

 

DUDES!

I'm getting the above mentioned PCM this afternoon and going to install immediately! The guy went EFI and removed the opti and PCM from the equation.

Wish me luck!