Why would my '91's TPI 5.7 ltr run great for 10 minutes after a cold start but then start to idle rough and try to die when I give it throttle? It starts to knock also. Ive replaced the ECM and the O2 sensor. It does not throw any codes so Im shooting in the dark. My next guess is to replace the EGR valve but Im tired of just spending money on parts that arent bad. Can anyone help?

 

I have this problem as well with a 91 z28 with a 305 with TPI. It will run until it comes up to operating temp and then dies and will not star until it cools down. Did you find your problem? I am going to continue to look versus replacing parts.

 

hook up a vacuum gauge and fuel pressure gauge. if no codes present then you have a problem the ecm can not see. Like a dying fuel pump, plugged cat, egr solenoid causing egr to open and killing motor, bad multec injector shorting and the injector drivers shutting down.