Another poor cold morning engine! - Third Generation F-Body Message Boards

Bob James · 07-30-2002, 08:41 AM

We have a 1989 Trans Am with 305 TBI.

Only in the morning and late at night the car engine will begin to 'buck' or stutter on acceleration. I think it is only when the outside air is cold, less than 50 degrees. It could be the ouside air or engine itself that is a factor.

We did the tune up routine, changed the EGR valve, have takin it to three separate mechanics over the course of three years.

We are resigning ourselves to take it to GM this time and pay the $$. This forum is the last check.

As long as it is a nice day it runs fine. Wife wants to sell the car now she is disatisfied. Guess we better sell it during mid day!

My guess is it has something to do with a temperature sensor. Either it is measuring the outside air, or maybe the engine itself.

It will do OK for the frst five to ten minutes, but after that the car will hesitate and rock. It gets us home, but is not fun. It doesnt clear itself up once it begins.
Any ideas?

F-BIRD'88 · 07-30-2002, 10:27 AM

Sounds like an ignition problem. Moisture related. Like at night when the dew is out. What happens when it rains?
Might try putting a heat lamp under the hood all night and see if this stops it. Then if that is it. you'll have to figure out what component is being affected by the moisture.