Truck cranks and runs fine until it reaches temperature then it shuts off

SCOTT FITZGERALD

MEMBER
2004 CHEVROLET TRAILBLAZER
4.2L
6 CYL
2WD
AUTOMATIC
120 MILES

Crank it back up and it's missing wont stay running unless you keep it running by pumping the accelerator. With that being said I have recently put a new head on it cause it blew a head gasket so I have had the harmonic balancer-crank sensor-cam sensor off so it needed to have the relearn process done so I took it to my buddies shop and he done it did not fix it so I left his shop and the first opportunity I got I held the accelerator to the floor it did not want to shift into second but when I came to a stop it was running perfect, but before I got home it started back doing the same thing.

Monday, January 6th, 2020 AT 5:33 PM

1 Reply

SCGRANTURISMO

MECHANIC
4,897 POSTS

Hello,

This sounds like you could have either a Crankshaft Position Sensor[CKP that is starting to fail, or you have an intermittent condition going on in the wires for the CKP that happens when the vehicle gets to operating temperature. In the diagrams down below I have included the location and instructions for the CKP in your vehicle as well as the engine management wiring diagrams including the CKP circuit, which I high lighted for you,and guides on how to induce and correct intermittent conditions in an automotive electrical circuit. You will need to be able to use a Digital Multi-meter [DMM] to go through some of these guides, so here is a link below explaining the use of one:

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Please go through these guides and get back to us with what you are able to find out.

Thanks,
Alex
2CarPros

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