Mechanics

CHEVROLET IMPALA ENGINE PROBLEM

2003 Chevrolet Impala • 63,000 miles

My 2003 Impala is having issues starting. It will do cold starts, mornings (or 4-5 hours resting), just fine. The car will stall if the engine is warm or hot. I have to keep the rpm's up for 45 seconds or so in order for the car to "settle" and idle on its own without stalling. Usually I have to drive while maintaining rpm's around 1200-1500, gas pedal + brake pedal, or it stalls when slowing way down or stopping. After I drive for a few minutes the car seems to have worked out the kinks and I no longer have to worry about it stalling out. The Check Engine Light was on a month ago and was throwing a low input Mass Air Flow Sensor code p109 I think. I replaced the MAF sensor, air filter, idle air control valve, spark plugs, and fuel filter. Also cleaned the throttle body and have used a couple bottles, at seperate times, of fuel injector cleaner additive when I filled up the tank and I do not think there is a vacuum leak.
What should I replace next?
Any ideas as to what the heck is wrong?

It seems as it is misfiring at the initial start up and idle or something but only after it has been driven from A to B.

Help!
Avatar
ChevyImpala03
October 19, 2012.




Start with fuel pressure check. It should be 40-45 lbs.

Roy

ASEMaster6371
Oct 19, 2012.


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