88 Olds Cutlass Ciera Quits after warm up

88 Olds Cutlass Ciera 2.8 multiport. Engine starts up and runs great when cold. It quits as soon as engine warms up, the idle will go up and down, then it quits. It's really hard to start it back up,I have to hold the accelerator downand and it cranks alot before starting. Then it's hard to keep running, and seems to be running very rich. If I hold the RPM's to 2500 to 3000 to keep it running, the exhaust will get supper hot. The converter gets red hot. I first thought the converter was pluged, so I pulled the converter off. Started right up, and ran great as did before when cold, until the engine warms up, then quits again and is hard to start back up again. I have a spare 2.8 engine, so one component at a time, I changed the Control Module, Fuel Rail for the fuel regulator, Idle Contorl Valve, TPS Sensor, Knock Sensor, I have replaced the fuel filter,fuel pressure is 46lbs at key on, 40lbs when running. Not pulling any codes Running out of ideas. Any help would be great. Thanks, Wayne

Was the passage/port that the IAC clear and open?

If it was partailly clogged it can contribute to some of this.
Did you tested any of those componets you replaced from the other motor?

Also that pressure with the key on is high.
Should be between 30-44 PSI.

Might try replacing that fuel pressure regulator.

Here is a link (http://www.autozone.com/servlet/UiBroker?ForwardPage=/az/cds/en_us/0900823d/80/0f/3b/4c/0900823d800f3b4c.jsp)that will help you test the IAC and TPS and a few other things in your fuel system.

Hope that helps!

Thanks for the reply, I replaced the fuel reg. after I replaced the fuel filter. I did check the componets from the other engine, and the other engine ran fine before it was pulled. It seems like it's something efecting the timing since the exhaust got realy hot. I haven't replaced the crankshaft position sensor yet,so I am going to try that. Thanks for the help, Wayne

I wouldnt worry about the CRANKshaft sensor.. yet... it would have to be dislodged to move the timing.
If it goes you loose ignition toally..engine quits.

It does sound like its starting rich..
Could it still be choking or rich starting remains on?
Check your coolant temp sensor.. is it working on the dash?

Check you plugs and see if its dying from too much fuel.. Black wet.. etc.
I know the O2 sensor will lean out the engine if it works right to get the 14:1 mix close after a warmup.



Good Luck

It is not getting to hot.the coolant temp only goes about a quarter on the guage. I will try pulling a plug after it stalls, to see if it is running rich. Thanks, Wayne

It ended up being a bad ECU. I changed the computer,and all problems were gone. Thanks for all the help. Wayne