Mechanics

STALLING AT IDLE

2003 Chevrolet Impala • 85,000 miles

I have a.2003 impala 3.4 with a stalling issue it only flags a P0101 code. I have replaced the Maf the Map the convertor and it still comes back I have checked the wiring tightened all the pin connections and check the voltage at the Maf it takes about 40 minuties before it stalls and normal freeze frame data shows a LT fuel trim at 135 but when it is running good LT fuel trim is -30 at idle out of idea's? Help
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Callenrsue
June 25, 2012.




This link just brings me back to my own question?

Tiny
Callenrsue
Jun 25, 2012.
Try cleaning the idle air control valve and see what happens-be adviced this is not an easy fix-What have you checked so far?

Tiny
Rasmataz
Jun 25, 2012.
I have cleaned the idle air the throttle plate. Replaced the Maf sensor the Map sensor. Did a back pressure test on the exhaust it was 2psi at idle and 7-8 on throttle snap. Replaced convertor thought maybe crank sensor 3x sensor replaced it. I will recheck the idle air motor unless you have any other ideas? Thanks

Tiny
Callenrsue
Jun 25, 2012.
Recleaned IAC and replaced still the same results. P0101? And stalls while just idling. Tps checks out 50psi of fuel pressure regulator is working holds vaccum. Swaped out MAF with a different Maf still same results.
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Tiny
Callenrsue
Jun 26, 2012.
.2psi of back pressure is too much but un related. Did u try a new gas cap? And also check the canister by the gas tank

Tiny
Mikederouin88
Jun 29, 2012.
Check for any of the following conditions: a) An incorrectly routed harness. Inspect the MAF sensor harness to verify that the harness is not routed too close to the secondary ignition wires or coils, solenoids, relays or motors.

B) A low minimum air rate through the sensor bore may cause this DTC to set at idle or during deceleration. Inspect for any deposits on the throttle plate or in the throttle bore and any vacuum leaks downstream of the MAF sensor.

C) Inspect for any contamination or debris on the sensing elements of the MAF sensor.

D) Inspect the air induction system for any water intrusion. Any water that reaches the MAF sensor will skew the sensor and may cause this DTC to set.

E) A wide open throttle acceleration from a stop should cause the MAF sensor parameter on the scan tool to increase rapidly. This increase should be from 3-10 g/s at idle to 150 g/s or more at the time of the 1-2 shift. If the increase is not observed, inspect for a restriction in the induction system or the exhaust system.

F) A skewed or stuck TP sensor.

G) A skewed or stuck ECT sensor.

H) The barometric pressure used in calculate the predicted mass air flow value is initially based on the MAP sensor at key ON. When the engine is running the MAP sensor value is continually updated near Wide Open Throttle (WOT). A skewed MAP sensor will cause the calculated mass air flow value to be inaccurate and may result in a no start condition. The value shown for the MAP sensor display varies with the altitude. With the ignition switch in RUN position
and the engine OFF, 101 kPa is the approximate value near sea level. This value will decrease by approximately 3 kPa for every 1000 feet 305 meters) of altitude.

I) High resistance on the ground circuit of the MAP sensor can cause this DTC to set.

J) Any loss of vacuum to the MAP sensor can cause this DTC to set.

K) High resistance on the ground circuit of the ECT sensor can cause this DTC to set.

Problem could also be caused by aftermarket accessories.

KHLow2008
Jun 29, 2012.

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