Irregular starting

JUSTICE SWEENEY

MEMBER
2000 GMC SIERRA
5.3L
V8
2WD
AUTOMATIC
280,000 MILES

Truck has trouble starting when it’s cold. It will turn over just fine but won’t start immediately. It usually takes 2 or more tries, but once it catches the right amount of fuel, it gets going and stays running good. I’ve done a regular tune up (plugs, plug wires, fuel filter, ect.) Replaces the MAF Sensor, the fuel pump, the coolant temperature sensor, and I took off the steering column cover and tightly secured the little wiring harness that goes into the ignition cylinder. I’m not sure what else to try, any suggestions?

3 Replies

ASEMASTER6371

MECHANIC
52,797 POSTS

Good morning,

When it is cold, I would check the fuel pressure to b sure you have the proper fuel to the injectors. My concern is that an injector may be leaking down overnight resulting in no pressure in the morning.

https://www.2carpros.com/articles/engine-cranks-excessively-before-starting

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

When it does not start, does the tachometer move up a little while cranking?

Is the check engine light on? If it is, do you know the code?

Roy

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Tuesday, January 14th, 2020 AT 2:49 AM

JUSTICE SWEENEY

MEMBER
2 POSTS

Unfortunately, I live in a town with no major auto parts store. So I’m currently seeing if I can borrow a tester from a local shop. The service engine light was on, but after the MAF sensor was replaced, it went away. I’m not sure on the tachometer, hopefully tonight it gets cold enough for me to check. Also, I’m not sure if this is related or not, but once the truck shifts into gear, it drops it’s rpm down for half a second and then continues as normal.

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Tuesday, January 14th, 2020 AT 3:45 PM

ASEMASTER6371