Toxie Posted October 9, 2011 Report Share Posted October 9, 2011 (edited) Does anybody have an idea on this one? This started today out of the blue… (Fixed...see bottom of thread, it was the IAC valve) I have an ‘89 Grand Prix, 3.1… I turn the ignition over and it may fire but will not start. I give it some gas pedal and it will fire and start. I keep it at around 1,000 rpm and it will run fine, let off the gas pedal and it dies immediately. No spit or sputter, just dies. Today I replaced the fuel filter and checked the fuel pressure at the rail. I had the minimum psi specs with both the key on engine not running (40psi) and engine running (32psi). The air filter looks fine. I checked and cleaned the IAC valve. I have replaced the following items within the last 10,000 miles. Spark Plugs Plug Wires Ignition Coil Packs (3) EGR Valve Idle Air Control Valve (IAC) Oxygen Sensor Coolant Temp Sensor Throttle Position Sensor PCV Valve Air Charge Temp Sensor (MAT) ECM (Computer) Fuel Injectors (All 6) Any ideas where to start from here?? Thanks Guys! Edited November 7, 2011 by Toxie Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted October 9, 2011 Report Share Posted October 9, 2011 are you getting a low battery maybe? Quote Link to comment Share on other sites More sharing options...
Andrew Posted October 10, 2011 Report Share Posted October 10, 2011 IAC is always my first thought in this instance. How does it run otherwise? MAP sensor if not so well. Quote Link to comment Share on other sites More sharing options...
Mel87 Posted October 11, 2011 Report Share Posted October 11, 2011 Maybe vacuum leaks somewhere? Quote Link to comment Share on other sites More sharing options...
AWeb80 Posted October 11, 2011 Report Share Posted October 11, 2011 IAC or TPS is my first guess.... Quote Link to comment Share on other sites More sharing options...
GTP091 Posted October 13, 2011 Report Share Posted October 13, 2011 Also check the harness at your map is all good, not loose, or broken wire. My old harness had a broken clip and would sometimes fall out and the engine would act exactly like this. If I had to bet I would think awebs suggestion on the IAC valve is the best. Quote Link to comment Share on other sites More sharing options...
Toxie Posted November 7, 2011 Author Report Share Posted November 7, 2011 Got it fixed! It was the IAC valve. The valve was stuck all the way out choking the engine as soon as you let off the gas. The one I had was only 6 months old and looked new, it shows even new parts fail... Thanks Guys, I appreciate it! Quote Link to comment Share on other sites More sharing options...
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