need help

I have a 1988 Chevy Celebrity, 102000 miles, when I 1st start the car it runs rough but then shortly the check engine light comes on and the call smooths out. This has been going on for a long time. However recently after I have driven the car for a while the car wants to run rough and wants to die. It seems to do this after the car get warm because if I let the car sit and cool down it will start up without dieing. I had replaced the oxygen sensor at one time and this didn't help the problem.

 

You need to retrieve the engine codes.

To do this, locate your diagnostic port (usually drivers side under dash) and jumper terminals A & B with a paperclip.

Once it is jumpered, turn ignition on and count the flashes from the check engine light.

It will initially give you a code of 12 (1 long flash, 2 short flashes).

AFter this code, count the new one.

 

Here's a little help on the reading:

http://www.troublecodes.net/GM/

 

There is a lot of things to check and it is nice that we are now able to find out codes. But in many instances of having cars run rough, misfire, etc., it might be good to check the plugs before the car runs good again, to see if something like anti-freeze (blown head gasket, especially if you can't account for engine coolant loss) is getting in a cylinder as sometimes a cold start rough engine or miss can be attributed to that. Or, if always the same cylinder is wetter with (unburned)gas than the others. Also with plugs out you can 'read' them all and perhaps even take compression test. If nothing else, and say this all has nothing to do with your problem, in future you will have a benchmark to start with.