I have a 1988 Pontiac Trans Am GTA, 305 TPI, 4 speeds auto, 3.27 rear and every options except the 350 TPI and leather.

My car doesn't run well. When I start it, it always start right away. But die almost 2-5 seconds after if I don't give it gas. If I don't stay on the pedal at least half-way, it stall anyway.

I have been to Canadian Tires and they say it's the computer in my car doing that. They said that when the car was connected to their "big" machine to read codes, sensors and all, the car died, and my computer was saying it was still running at 500RPM. So they got my computer out and give it a couple of "taps" while it was running and suddenly it was running better. When you give it some more "taps" it doesn't run good again and stall.

Do you think the problem is indeed the computer itself? I have new cap/rotor, sparks plugs and wires, fuel/air filter, I've put some fuel treatment in the gas I cleaned the IAC and TB.

Also, when I wanted to remove the chip from my computer, on the chip it's indicated ADS Super Chip. What the hell is that? Is it an aftermarket chip or it's stock? The model # is 8818-B and I can't seem to find anything about it on the 'net.

 

Clean the TB out completely and reset the IAC and TPS to spec than work from there

Reset the ecm after doing this also

Follow the tech article posted here

Eliminate the dumb stuff first

Hard to say if its ecm related or not, but if you could duplicate tapping on it and the condition changing I would consider it suspect as well at this point

Also is this with car cold or hot or all the time etc.

What did the other sensors read while it was running etc

later
Jeremy

 

A month ago my mechanic connected is scanner to my car and all sensors and things were right on with no SES codes. The car was working fine at the time.

Like I said we already cleaned the TB and IAC and checkout for dumb stuff.

I just removed my computer from my car today and it say remanufactured by GM so it already been changed in the past. Is it a common problem or what? And what is an ADS Super Chip like I said?

 

I've never heard of a ADS super chip on a stock PROM/ECM so it isn't a stock PROM and I never heard of the company. No matter, your ECM/PROM doesn't sound right.

Didn't you buy a new ECM last week? You likely don't have it yet but plug it in when you get it and see what happens.

I just bought one too for my 87 GTA since I am getting no output on the IAC circuts. It's on it's way. Scored a 730 spare from the scrappers today too. Don't need it but if/when I do, I have it. There are a few dozen parts I like to have spares of.

 

No one ever heard of ADS Super Chip 8818-B that I have? I did some research on the Internet, but did not find my exact chip. It says for other chips from this company, that when you have the letter "b" in the product code, you need to remove the cat and put a lower temp thermostat... I actually had no cat on the car when I bought it, but the thermostat been changed to a 195 like originally on the car. Can it cause troubles? I didn't know about the chip so that's why I've put a stock 'stat. Should I buy a GM chip? Will it works good since I don't have a cat anymore? Where is the cheapest place to get a new GM chip?

I've bought a used computer from someone on this board. I should receive it at the end of this week or early next week. I hope it's my problem because the car was supposed to go in storage before november 1st

 

?

 

Anyone?

 

This is a common failure mode for the '165 ECM (the one your '88 has). Yes, the ECM is bad.

The tap test is used for the ECM and MAF, if upon tapping on either the engine suddenly runs better or worse the tapped-on part is bad.

RBob.

 

Ok, I hope the used computer I've bought will be good...

But anyone know about the ADS Super Chip thing?

 

I had the same problem on my 91 its the ecm. I don't mess with ecm's I buy new because the reman junk out there doen't have a good track record for lasting very long, and you never know what your getting used. If you still have problems with the used one I would look into a new one. The stealer ships still carry them last time I checked.

 

Well people, I think I've found the problem...

I've bought a used computer from a member here that was supposedly in working condition. After installing the compute I just received, my car was doing the same thing. I was so mad I don't have much cash and it wasn't the problem...

I unpluged the MAF's connector and the car runned without stalling!

Now I know for sure that my "Service Engine Soon" light works hehe.

But can I run my car like this with the connector on the MAF unplugged? I need to go put my car in storage this week and I don't have enough cash and time to find a good used one so I was wondering if it will damage anything and what will it do running without the MAF connected?

 

If you tap on this computor does the engine running condition still change? If not then it isn't doing the same thing as before, and, you had two issues: a bad ECM and a bad MAF.

Yes, you can drive the car with the MAF unplugged. Just don't race it.

RBob.

 

It's Canadian Tire that told me that, when I tapped on the ECM myself today it wasn't running any better...

So right now it's my old ECM back in, with the connector on the MAF unplugged and it doesn't stall anymore. Even if I don't race my car, can I damage something? I'll have to make a trip of at least 45 minutes to store it and 45 minutes to come back this spring.

 

ADS is just an aftermarket computer chip maker, along the same lines as Hypertech. I am not sure if they are still around. Not really a good upgrade, since they are pretty generic as far as the programming.

 

Jay: Is it still better than the original GM chip, worst or pretty much the same? I've found some ADS chips on the 'net but not my #. I think the letter "B" at the end mean that I need to run the car without a cat and with a lower temp stat. I did not know that and in the past I changed my stat for a 195 one... Does it make any difference if I still use my 195?

So my problem was my MAF and not my ECM... Can I use any MAF from 86 to 89? 305/350 TPI? Camaro/Firebird? Because I've found one from a 87 Camaro with a 305 TPI but I don't know if I can use it on my 88 GTA.

Thanks