HI. I am new to this forum so here goes.
I have a 88 Corsica 2.8 EFi that will run fine for awhile until warm. After,depending on the outside temperature, it dies after running from 20 minutes to 2 hours. It can be restarted and will run for at most a minute then dies again. After a couple of retries it will not start. If I wait for the engine to come to ambient temperature it will restart and the cycle starts again. There no error codes.I found one vacuum leak in the intake and repaired it. One thing i did notice is that when the cooling fan starts the engine stumbles until the fan is up to speed. When it stop the engine runs smooth until it again just stops. Has anyone had this problem? If so what was the fix? Any help is appreciated. Thanks

 

could be the ignition module. a parts store might be able to test but make sure they test it a few times to heat it up

 

That's what I thought too. I replaced it and the issue is still there. I did have that in the past.

 

May sound odd, but when was the cooling system flushed? I had a new 88 Corsica with 4 speed manual, but that was awhile back.

 

Due to my replacing the motor mounts and had to remove the radiator, it is all new coolant. This problem has been going on for about a year now.

 

have you checked the fuel pressure?

 

Yes.It is in specs per the manual engine running and not.

 

I have the same problem