95 gmc with the 6.5 truck started bucking and coughing and dying running its self out of fuel replaced fuel pump relay and did not help put test light on lift pump and it only has power fed to it when the ignition is in the crank position, and no other time it is my only vehicle so for the time being i ran a toggle switch to lift pump and it runs fine. i dont know what tells my lift pump when to run i am guessing the pcm controls it but not sure, any help would be greatly appreciated
-
Welcome to The Truck Stop! We see you haven't REGISTERED yet.
Your truck knowledge is missing!
- Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
- We have tons of knowledge here for your diesel truck!
- Post your own topics and reply to existing threads to help others out!
- NO ADS! The site is fully functional and ad free!
Problems registering? Click here to contact us!
Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!
lift pump issues please help
- Thread starter cookman7
- Start date
- Staff
- #2
You need a new OPS (Oil Pressure Switch), cookman. The OPS supplies pwoer to the Lift Pump whenever oil pressure is available - when your engine loses oil pressure, the OPS will cut power to the LP (handy in the case of an accident)
Call Leroy at www.pmdcable.com - he is one of our vendors here. His vendors' forum is http://www.dieseltowingresource.com/forumdisplay.php?f=194
Call Leroy at www.pmdcable.com - he is one of our vendors here. His vendors' forum is http://www.dieseltowingresource.com/forumdisplay.php?f=194
Mudbath
Old Smoky
The oil pressure switch takes over when the key is in the run position. Replace it with a AC Delco and all should be good again. It is not recommended to bypass the oil pressure (permanantly)as it is a safety device.
vail426
Member
Cookman-- The LP relay ONLY powers the LP when the engine is being started.
Rodd
Recruit
If you don't need the truck for a few days I would buy an ops extender from pmdcable.com. He is a sponsor of the site. For $20 it's a 5 minute or less job the next time. This time if it is your first time you're looking at about 2 hours if you're lucky. I just replaced mine but didn't have time to wait for the extension.