Engine will not start

2005 GMC SIERRA

1,600,000 MILES • 4.3L • V6 • 2WD • AUTOMATIC

CHRIS LYNCH

MEMBER
1 POST

Checked Schrader valve and fuel burned off after a few seconds. Replaced bad fuel pump with AC Delco OEM Fuel pump and now the valve is showing consistent stream of gas but still won't start. Cranks and turns on for 1 to 2 seconds then cuts off. Tried Re-learn procedure for key hoping that the anti-theft was stopping it but still no start. What could be wrong?

Dec 21, 2021 at 2:41 PM

KASEKENNY

✓Experienced Mechanic
18,907 POSTS

There are a number of things that could cause this so if the engine is starting and stalling then we need to continue to look at a fuel issue but also spark, compression, and air.

https://youtu.be/dCjmRL3p4Cs

Has this vehicle been sitting for a while or was it running in the last month?

If this vehicle was sitting, did you put fresh fuel in it when you replaced the pump? If not, we need to start there. Old fuel will cause a start and stall.

If this is fresh fuel, then we need to monitor the actual pressure.

The fact that the engine will start, and stall means we are getting spark at least momentarily, compression, and air.

So that means we need to stay focused on fuel until we eliminate it. There is still a chance that you don't have enough fuel even though you have a stream coming out of the valve.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

So, let's start with getting the pressure and go from there. Thanks

Dec 22, 2021 at 10:21 AM

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