2001 Pontiac Grand Am Car stops occasionally.

SSIHABDEEN

MEMBER
2001 PONTIAC GRAND AM
6 CYL
FWD
AUTOMATIC
64,000 MILES

Occasionally, car stops when braking and/or turning and or stopping. Engine can be stsrted right back. Did several things including repairs recommended by dealer after diagnosis. They told me there was excessive carbon deposit at several places and wanted thorough cleaning. I did all those including combustion cleaning, new air filter, cleaning air intake manifold, new fuel filter, etc. Some other mechanic suggested cleaning/replacing IAC (don't know what it is or I may have heard it wrong) which is the only thing left to do. I am really tired of this car now.

I will appreciate any suggestions / help you can provide. I will mail the donation if you can give a mailing address.

1 Reply

ZACKMAN

MECHANIC
4,202 POSTS

ROUGH, UNSTABLE OR INCORRECT IDLE, STALLING

Symptom Definition

Engine runs unevenly at idle. If severe enough, vehicle will shake. Idle may vary in RPM. Either problem may cause stalling. Engine idles at incorrect RPM.

Possible Cause & Correction

Check the following items:
Ensure throttle linkage and/or TP sensor is not sticking or binding. Ensure throttle bore is free of
foreign material.

Check for proper operation of crankshaft position sensor.

Check for proper operation of camshaft position sensor.

Check for vacuum leaks.
Check engine idle speed (both base idle and PCM idle).
Check Idle Air Control (IAC) system. Check for vacuum leak or high idle. Check for alcohol contaminated fuel, incorrect fuel pressure or a restricted injector. Check for foreign material in
IAC bore of throttle body. Check for proper connection of IAC valve electrical connector. Check
for failure of A/C compressor or relay.

Check for proper operation of EGR system.

Check charging system output. Repair charging system if voltage is less than 9 volts or more than
16 volts.
Check for fuel in pressure regulator vacuum hose. If fuel is present, replace regulator.

Check evaporative emission control system.
Check for proper spark plug gap, and check engine compression.
Check PCM grounds for clean and tight connections.
Check Manifold Absolute Pressure (MAP) or Mass Airflow (MAF) sensors for proper operation.