Starts and runs cold and shuts off when at operating temperature?

G7CUSTOMER

MEMBER
2006 CHEVROLET 1500
5.3L
V8
4WD
AUTOMATIC
13,000 MILES

The truck starts and idles fine and drives for a few miles, but when it gets up to temperature, it starts misfiring, idling bad and shuts off. I'll wait 30 minutes and will start up again.
I changed fuel pump, MAP sensor, Mass air sensor, crank sensor, cam sensor. Coolant temperature sensor.
New Chevrolet long block installed 13,000 miles ago right from Chevrolet.
I'm at a loss.

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,544 POSTS

Hi,

When it stalls are won't restart, we need to see if you lost fuel or ignition spark to the engine. One is likely missing.

Do this. When it won't restart, see if it will start if you use starting fluid. If it does and then stalls, we know it is fuel related. If there is no change, I need you to check if there is spark to the plugs.

Here is a link that explains how that is done:

https://www.2carpros.com/articles/how-to-check-for-ignition-spark

I realize you replaced several things. However, we could have a failing relay or another simple component that is failing until it cools. Also, let me know if you have access to a live data scan tool. I would like to know if the coolant temperature sensor is providing a proper signal and the short-term fuel trims if possible. If you have been able to retrieve diagnostic trouble codes, let me know what they are.

Let me know.

Joe