brewersprts

iTrader: (2)

So I recently came across a decent deal on a 97 TA. It ran a little rough but it was rust free and I was ready to buy right then.

Well it's running very rich. A code reader and a proper scanner will not communicate with the car. I don't see any burned out wires or anything in the wiring harness or any bad grounds or anything else that would make me think it was something else. I assume from this that the computer is bad. Any other suggestions?

I really think I need to this first because all the simple stuff I checked hasn't shown any problems. Heck it might even just be the computer making it run so rich.

What do you guys think?

SS RRR

iTrader: (2)

Might have been converted to OBDI therefore an OBDII scanner will not communicate with it. For the life of me I don't have an idea how one can simply tell whether it's OBDI or II.

ahritchie

iTrader: (1)

You need to scan it properly somehow, take it to a dealership if you have to. Could be any number of sensors; MAF, O2's, coolant temp sensor, ect. ect......The PCM itself is almost never the culprit; it is simply interpreting the data (wrongly) from whatever sensor that is FUBAR is misinforming it.

brewersprts

iTrader: (2)

Also, what computers can I use? OBD2 started in like 95 or 96 I think, so it has that be that or later. Does it have to be a six speed as well? ( my car is a 6 speed). If I happen to find a wrecked formula will that work too?

Will I have to get it flashed or something like that so the car will start since it has one of those chipped keys? The chances of me finding a computer from a car with the same number key is slim to none. As far as the security system is concerned, does it make a difference if I buy a brand new computer or a used one?

Thanks for any and all help. I want to get this thing running properly and don't want to just throw money at it guessing.

ahritchie

iTrader: (1)

There's a 99% chance it's NOT the PCM at fault here. Is the car modded at all?

brewersprts

iTrader: (2)

I did take it to a dealer. He's the one that told me his big money proper scanner wouldn't communicate with it. He suggested that it needs another computer so he can connect with it and see what's wrong.

brewersprts

iTrader: (2)

The engine seems to be stock. But the car does have cold air intake and a full exhaust from the headers back.

ahritchie

iTrader: (1)

LMAO, sound like said dealership is incompetent; maybe ask Autozone to scan it for free or someone who is familiar with these cars? You need to list the mods if any, it could be something the previous owner did or didn't do.

brewersprts

iTrader: (2)

What else would make the car not be able to communicate with the scanner ( a proper scanner, not my stupid $100 code reader).

ahritchie

iTrader: (1)

Also, define what you mean by "running rough" it could simply be running on 7 cylinders or something and just need a simple tune up....it happens. What's the mileage?

brewersprts

iTrader: (2)

I find a lot of times people at dealership are incompetent. Idk if they just want to sell your parts or just want to keep charging me money while they guess what is wrong. Who knows. I try to do as much as possible myself but after over a week I am stumped. Which isn't saying much. Lol

brewersprts

iTrader: (2)

It is running very rich. I could tell that when I pulled the plugs. Also, when driving behind it you can sure smell the gas. Also, it has a little black smoke under WOT. At 70mph it also used almost half a tank going about 50 miles on the drive home.

The fuel pressure is good, all cylinders have good spark. One plug didn't look any worse or better than all the other ones. The opti isn't full of antifreeze which is kinda what I first thought, and hoped, because that's simple enough to fix. Just time consuming.

The car has 130,000 miles

ahritchie

iTrader: (1)

That, I don't know, maybe some PCM experts will chime in....even if it was switched to OBD1, the dealership should be able to scan it for codes, my car has the old OBD1 PCM and they can scan it; probably with some old relic of a scanner from the 90's LOL... I'd get a second opinion somewhere knowledgeable with these cars. I hope you got a good deal on this car, sounds like somebody tried to unload a basketcase car they can't figure out on you. Personally, I would never buy a car that didn't run perfect because it can be a PITA to diagnose if you don't know the history of the car. It's possible, but somewhat unlikely that somebody who didn't know what they are doing tuned the PCM completely wrong, in that case a used stock PCM might be a solution, but who knows what was done or not done is the issue and what codes the PCM has stored. Is the service engine light on? How many owners did it have? If it's changed hands several times this could be quite an enigma to figure out....I'd ask whoever you bought it from all the history they know and get some other reputable place to scan it. Is there any GM performance shops in your area? There's tons of them in my area that know these cars and how to scan them.

If you have a laptop, you might just want to buy one of these scan tools and download some free diagnostic software and do it yourself: http://www.aldlcable.com/allinone.asp

96capricemgr

iTrader: (1)

look for the service number on the pcm and verify if it is OBD1 swapped or the stock OBD2 pcm. Pretty common mod and the dealership would not even try to scan it as OBD1.

brewersprts

iTrader: (2)

The label that is on the PCM is so worn off that I cant read any numbers. I can tell that it's not the original PCM though, it's a remanufactured one.

Any difference between the OBD1 and OBD2 computer? On the outside that I could tell by looking at it I mean.

RedHotG8

iTrader: (1)

Just get a PCM from the same year and have it programmed for your car. You can buy one cheap on Ebay.

WS Sick

If you get a 96-97 puter make sure all your crank sensor wiring is there and hooked up.
If it does have all that still in place unplug the crank sensor and start it, if it starts and runs the same with no SES it's got an OBD 1 puter in it.

Ed Wright

iTrader: (1)

1994/1995 are OBD1, 1996/1997 are OBD2. Look the same, different service numbers on the PCM. The 8 digit PCM service number ending in 8051 is OBD1.

brewersprts

iTrader: (2)

That is some awesome information. Unfortunately, I can't read any of of the numbers on the PCM. That is awesome to know for future reference though.

moehorsepower

iTrader: (3)

If the dealer tried to download or flash a stock tune, they wont be able to, but they should be able to scan it..