1990 Chevy Cavalier dies when it warms up

check the ground on your negative battery cable

How does the car run when it is cold? It does not sound like an electrical issue to me. It may be an engine management problem. Such as a defective engine temperature coolant switch. Is your check engine light coming on? Are there any other problems electrically ie; dimming lights, trouble starting?

[quote:240a2b6627="backyardmechanic"]How does the car run when it is cold? It does not sound like an electrical issue to me. It may be an engine management problem. Such as a defective engine temperature coolant switch. Is your check engine light coming on? Are there any other problems electrically ie; dimming lights, trouble starting?[/quote:240a2b6627]

The car runs fine when it's cold. the check engine light doesn't come on, except when it dies, but goes off as soon as the car is started back up. Recently I have had some trouble starting the vehicle on a cold start, it takes 3 seconds for the engine to turn over. but when the vehicle is warmed up, it takes a little longer for the engine to turn over. thank you all for your time in helping me with this! 8o)

It still sounds like a engine management issue to me. Just because the check engine light doesn't come on doesn't neccessarily mean its not a sensor that can not be detected by the PCM. The reason I am leaning toward the Engine Coolant Temp sensor because the car runs fine when its cold but once the car warms it dies. This is one of the sensor that change with engine temp. One last thing I am assume that the basics ( plugs, wires, cap rotor. filters ) are good and have been maintained properly

[quote:ac60a1614d="backyardmechanic"]It still sounds like a engine management issue to me. Just because the check engine light doesn't come on doesn't neccessarily mean its not a sensor that can not be detected by the PCM. The reason I am leaning toward the Engine Coolant Temp sensor because the car runs fine when its cold but once the car warms it dies. This is one of the sensor that change with engine temp. One last thing I am assume that the basics ( plugs, wires, cap rotor. filters ) are good and have been maintained properly[/quote:ac60a1614d]

My veh is a 1990 and doesn't have a PCM. It does however, have an ECM, which is what I thought it may be, however, I really don't want to keep throwing parts at it, especially expensive ones. lol everything has been maintained properly since I've had the veh, including trany flush, radiator flush, all filters (e.g fuel, air, oil, etc.), power steering flush, and I think I had an engine flush if that's possible. Its really a pain in the rear to get to my ECM and sensors with the exception of my map sensor. Any other suggestions? Thanks again!

I don't think the EMC is bad, they don't go bad that often. If the car doesn't run bad once it warms up then maybe this something you may want to live with. LOL I can't think of anything else to check.
Good luck

Now that I've had this problem and it kicked my behind until I got it, This is easy! The problem is that when your engine warms up, obviously it expands ever so slightly. Well guess what.. Those old O-Rings on your fuel injectors aren't capable of expanding anymore! The lack of correct pressure causes your engine to run like garbage but won't throw any error that will tell you this is the problem. Only buy genuine parts when it comes to seals. I can't stress that enough. 30 bucks and you're back in the game!