Chevy/GMC Small Trucks Forum Discuss the Colorado, Canyon, Sonoma, S-10, etc here!

Fuel Pressure Woes

Old 07-25-2012, 08:21 AM
qws is offline
Thread Starter
Join Date: May 2012
Posts: 13
Default Fuel Pressure Woes

I'm actually helping a friend out with is GMC 4.3 V6 its a 1998.
His symptom is when the truck is cold it will start fine and run 15,30 min's. then it will stall out and not start back up.
Temp is running at 210
Its not throwing any codes

I put a fuel pressure gauge on the truck along with a spark tester. Started the truck up when cold. FP was 51 and spark showed a nice strong light.

After a few min's the the FP dipped down to 40psi and the truck stalled. On restart FP was 40, spark was fine but didn't start up.
Sat for a few min's, turn the key FP up to 60 and starts up.

The whole time spark is fine so this is defiently a fueling issue.

Turn key on... pressure jumps to then drops to 0
Turn key off.... pressure again jumps to 60 then 0

So at this point I do believe the system is losing pressure... I did replace the FPR and that didn't solve the problem except that now when its running the pressure stays constant and it will run smoother until the psi drops off again.

The fuel pump relay is working.

I plan on removing the tank today and taking a look at the fuel pump.

Do you think I'm going in the right direction? anything else I should be looking at?
Old 07-26-2012, 06:15 AM
qws is offline
Thread Starter
Join Date: May 2012
Posts: 13

Put in a new fuel pump, pressure came right up and stayed.
Ran great.

Thanks for your help!
Related Topics
Thread Starter
Last Post
Chevy Silverado/ GMC Sierra Forum
11-28-2010 12:45 PM
Chevy Silverado/ GMC Sierra Forum
09-05-2010 10:55 AM
Chevy Silverado/ GMC Sierra Forum
02-18-2010 02:03 PM
Chevy Silverado/ GMC Sierra Forum
05-01-2008 07:33 PM
Chevy Silverado/ GMC Sierra Forum
04-02-2008 09:00 AM

Thread Tools
Search this Thread
Quick Reply: Fuel Pressure Woes

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.