2001 Chevrolet Impala Having Intermittent Crank Condition Happens Key

first of all, never turn to start with it running, you will damage the flywheel and start motor nose.

the ignition switch is a common failure.

Roiy

when I will start check the voltage at the starter with the key in crank position. If there is voltage to the starter try tapping it with a hammer doesn't crank? shifted into neutral doesn't crank? If there is no voltage to the starter go to the ignition switch and check for start signal on the Brown wire when a key is in crank position. If there is no signal from the ignition switch the switch is bad. If the switch is sending a start signal then you'll have to go to the neutral safety switch.

Right, It will clash

I wish the no crank problem would just fail. If I test the ignition switch for continuity it would pass because car is cranking fine this week.
It only happens once a month every month.

What about the no crank while running feature, could that be a problem. If I replace the ignition switch, and neutral safety switch, but the problem might still be there.

Is the no crank while running... PCM or vacuum controlled, Anyone know?

so when it won't start check the voltage at the starter with the key in crank position . If there is voltage to the starter tried tapping in with a hammer does it crank? shift into neutral does it crank.if there is no voltage to the starter go to the ignition switch and check for start signal on the Brown wire when the key is in the crank position. if there is no voltage is from the ignition switch the switch is bad if the switch is sending a start signal then you'll have to go to the neutral safety switch and check your voltages there.

Its upstream starter because there is no voltage at brown trigger wire while key in crank position.

Why the no crank while running? Anyone know?

Are There any TSB for a 01 impala 3.4l concerning:

"Starter disabled, service throttle"

did u check the voltage at the starter? also if it running y would u restart it?

No voltage at starter at in brown trigger wire while attempting to crank. Only when the problem happens.

I think the ignition, and neutral safety switch are fine.
could be the the "Starter disabled, service throttle" because it wont idle.
will crank and start right now but you have to keep your foot on the gas or it will stall.
Hey everyone lets take care of the stalling at idle condition first then that should be all. Thanks

this idle problem would set a code. Take it and have the codes checked. Most part stores will check your codes for you. You need to start here.

Ok I checked the codes with my scanner and I get codes P0300,P0420,P0420pd. Previously had a misfire for awhile.

closed O2 sensor reading fluctuates between .050v and .800v approximately, is that normal, or a little lean?

What is the fuel pressure suppose to be?

Fuel pressure is 52 psi at idle, and 58 psi at a quick full throttle.

Can you get me a better diagram of the starting system. I think is one of those integrated PCM systems. Thanks