'89 GTA Trans Am - runs rough when cold
 

Just bought an '89 GTA. It will start, but dies wen you press the accelerator. You can "feather" the pedal to keep it running, but it spits, sputters and backfires. Doesn;t have enough power to even move the car.
However - after a few minutes, and the car is warm... it runs and drives okay. But - say you turned it off, to run in a store for 10 minutes... when you come back out, it runs crappy again for about 1/2 block.

Any suggestions?

Re: '89 GTA Trans Am - runs rough when cold
 

It is carb or fuel injected and what kind of pump?

Re: '89 GTA Trans Am - runs rough when cold
 

It is fuel injected. Pump... no idea.

Re: '89 GTA Trans Am - runs rough when cold
 

Ok, have you done anything since purchasing it? replaced the spark plugs/wires?

If not then perhaps trying that in combination with a good bottle of injector cleaner might solve your problem. Though if it's all stock components from '89 it might just be old, just my opinion. Maybe someone else will have a more helpful suggestion, I'm better with carbs lol.

Re: '89 GTA Trans Am - runs rough when cold
 

I have run fuel stabilizer/injector cleaner through the tank. I replaced spark plugs yesterday, and will do the wires today or tomorrow.
Just wondered what would cause it to run so crappy when it's cool... but be fine (not spectacular) once warm.

Re: '89 GTA Trans Am - runs rough when cold
 

It sounds like being cold just exaggerates the problem if it still runs a little iffy when it warms up.

Re: '89 GTA Trans Am - runs rough when cold
 

It ended up being the Mass Airflow Sensor. If I unplugged it - the car ran like a champ. Plug it back in - ran crappy. So - I replaced it and it ended up running great.
But - immediately after the Check Engine Light came on, and it's throwing 8 different codes!

Any ideas? Any help? I doubt that changing the MAS created so much more trouble.
Codes:
41 - Cam Sensor
42 - Ingnition bypass
44 - Left bank O2 sensor (lean)
51 - Incorrect MEM-Cal
52 - Fuel cal-pak incorrect or missing
54 - Fuel pump circuit low voltage
61 - A/C system performance
63 - Right bank O2 sensor circuit error

Re: '89 GTA Trans Am - runs rough when cold
 

That's a lot of codes. Disconnect the battery for 5 or 10mins and let the ECM reset.
Then drive it a bit and see what codes you get. Some of those look like ECM memcal faults. Could be the previous owner may have tinkered with the ECM programing.

Re: '89 GTA Trans Am - runs rough when cold
 

I disconnected battery for quite awhile while I was working on other things. Hooked it back up, started the car... and the Service Engine Soon light came right back on. Someone told me to check the ground strap. I found one from the firewall that should have run to the passenger side head... not connected at all. I couldn't reach down to attach it... so I ran it from the firewall to the plenum.
Unhooked the battery... hooked it back up... still have SES light.

Re: '89 GTA Trans Am - runs rough when cold
 

Still getting codes 51,52? If so, I would suspect the ECM/memcal is the problem.

Re: '89 GTA Trans Am - runs rough when cold
 

Yes - SES light still on. I took the ECM out, popped the "chip" and re-seated it.
Still having the same issues.

I took pics of the ECM and "chip" but I don't know how to post them.

Re: '89 GTA Trans Am - runs rough when cold
 

I had 3 wires that broke out of the ECU harness, and went to the driver side head. nothing on the passenger side. I ran 2 brand new ground straps from the firewall to each head. Cleaned/roughed-up all contacts to ground.

When I first turn the key to start - the SES light does the "bounce" and remains on til the car is started. It then turns off - but comes right back on after about 5 seconds.

If I shut off the car, then turn key to on again - the SES light just remains lit. No bounce.

Re: '89 GTA Trans Am - runs rough when cold
 

Should I try a new MEMCAL... or ECU?

I would try a new mem cal, but that's just me. The mem cal regulates fuel which is code 52 and code 51 is the mem cal again.

Re: '89 GTA Trans Am - runs rough when cold
 

What's the code on the EPROM? http://www.3rdgenformula.com/89/promcodes.htm
Verify that code you have with the ones from the list. If they are different, obviously something isn't right.

Re: '89 GTA Trans Am - runs rough when cold
 

ECU and memcal are correct. But I've been told by some to change the ECU... and by others to change the memcal.

Re: '89 GTA Trans Am - runs rough when cold
 

Installed re-manufactured ECU. Used same PROM... car still runs like a champ, but is now throwing all the same codes (41,42,44,51,52,54,61,63) PLUS 45 AND 46 now!

So... try a new PROM?

Re: '89 GTA Trans Am - runs rough when cold
 

I would:imo:

Re: '89 GTA Trans Am - runs rough when cold
 

Okay - so was O'Reilly's code reader way off or what?
I went out and did the paperclip/SES light blink test, and the only code it is showing is 33... which is a Mass Airflow Sensor problem. THAT is what I originally replaced to get the car to run correctly... but the SES light has been on ever since.

Now what?

Re: '89 GTA Trans Am - runs rough when cold
 

Ok i have had same prob code in past i give u a list to check.
get to tdc. on cylinder one, then check to see if your timing is correct.
1 8 4 3 6 5 7 2

Then check on connection in cap and rotor. and coil connector in center of cap that touches the rotor button.

check all vacuum lines for cracks or dry rotting,

also check all your fluids mine end up being a blown head gasket that was sucking air.

It sucks because maf sensor code can be one of like 20 things its the dumbest code to pull if gives you NO insight to the prob check all that.

And i dont even know how u used the scanner at oreily seeing anything under i think 95 has to be done by the paper clip trick.

Did you replace the relays?