1999 Chevy Suburban UUUGGGHHHH!

HEATHERH1999

MEMBER
1999 CHEVROLET SUBURBAN
V8
4WD
AUTOMATIC
20,000 MILES

The burb won't start consistently. We replaced the fuel filter, the fuel pump works, and we changed the fuel pump regulator. It will start if we prime it with gas. So, we do that, let it run for a while, shut it off and if we turn the ignition back on within an hour it will start sitting any longer than that it will not. Also have an OBD code of 300 which is random misfire detected. Would that contribute to starting problems?

Out of ideas on the fuel system. Any thoughts?

Thanks,
Heather

5 Replies

MERLIN2021

MECHANIC
17,250 POSTS

Pump may be working but pressure may be low, or injectors are leaking down, the misfire code may be the rseult of it not starting! You didnt give an engine size, but some GM's need 60 psi to start without difficulty. test this way.
http://www.2carpros.com/car_repair_video/test_fuel_injection_pressure.htm
Go here and checkout our video.
You can rent the test gauge at Autozone.

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Sunday, November 2nd, 2008 AT 9:34 AM

HEATHERH1999

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5 POSTS

Sorry about that! V8 Vortec ( the one with the R in the vin) what does that mean about the fuel injectors leaking down? We thought maybe they were sticky because of sitting. Pressure was at 60 psi as you suggested.

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Sunday, November 2nd, 2008 AT 9:42 AM

MERLIN2021

MECHANIC
17,250 POSTS

With a test gauge attached, turn off ignition and see how fast it takes for it to loose 10 psi, if its quick, there is a problem somewhere, and if you changed the pump and the regulator, it's probably at least one faulty injector.

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Sunday, November 2nd, 2008 AT 10:15 AM

RATBOYCRUISER

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1 POST

I HAVE THE SAME PROBLEM BUT A CODE THAT READS LEFT AND RIGHT RUNNING LEAN WHAT DOES THIS MEEN ALSO WHERE IS THE FUEL REG FOR A 1999 CHEVY SUBURBAN

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Monday, November 10th, 2008 AT 11:49 AM

HEATHERH1999

MEMBER
5 POSTS

The fuel regulator pump is under the whole air intake system where the throttle body is. It took us 5 hours to change it out. What was the code you had?

Heather