Rough idle, low power, no check engine light
Asked by Jesse Mar 08, 2017 at 09:02 PM about the 2005 Pontiac Grand Prix Base
Question type: Maintenance & Repair
My car sometimes doesn't start unless I give it a
little gas. It sometimes hesitates from a stop.
Overdrive has very little power, and rpm are low
(too low). Most of the issues happen after I have
drove for about 30 minutes and go into a store. Ill
come back out and start the car but it immediately
dies. Then I have to give it gas.
5 Answers
beatupchevy answered 7 years ago
scan for codes even if the light isn't on ,
I have scanned for codes. I have none pending either. I got new plugs, wires, coils, fuel filter, and air filter. Cleaned the throttlebody and the egr valve tube and Maf sensor. That's about all I know to do.
beatupchevy answered 7 years ago
Either the MAP ( manifold absolute pressure) or the MAF (mass air flow) is sensitive and needs a certain cleaner , I believe it's the maf that can be damaged from carb. cleaners ,no codes are up so without testing or real time scanning you can't tell whats going on ,you're not giving it gas you're just opening the throttle and that sensor tells the computer what you're doing , but let us know what happens .
I have a scanner that shows live data. Its a cheaper one but I don't really know what to look for. I guess I don't know what the values should be.
Could be your ECM failing. Same symptoms in my car even after I changed all the stuff you did. Finally, replacing the ECM did the trick.
