The truck will run (continues to do so as long as you are moving down the road) after I hand prime it but goes dead after idling for a few minutes. When manually pumping it fuel with air bubbles come out of the hole next to the pump. Any suggestions on what needs to be repaired? Thanks very much for the help.
Air bubbles means it is sucking air. Check for rubber bits and pieces in fuel filters/housing, if so you will need to replace fuel line. if none, with the motor running you can take a can of starting fluid and spray around fuel line/filter mating surfaces and if a leak is found the motor should rev-up.
This happened once to me earlier this year, problem was the rubber gasket on the secondary fuel filter not being seated quite right and allowing air in. Did this happen immediately after a PM? That is what happened to my truck. Good luck, Jim
Bad fuel filter or separator. Like someone said air bubbles so you are sucking air. Change both again i would say.
fuel/water seperator has a check valve on the front side that sticks open pretty common. also if ou have leakage at the cups that can cause air in fuel issue, check out that valve first, then have the clear lines hooked up to the front of the head and check out the cups.
Problem got a little worse as it stopped on me while driving. Had someone check it out by putting some pressure on the fuel system and found the leak. Was coming from a line just behind the manual pump toward the cab. Hoping it holds out enough to make it back to the yard tomorrow to get it replaced.
This will not make the engine rev, your thinki THIS WILL NOT MAKE A DIESEL REV, your thinking of a car with a gas motor and that only works a the vacuum lines.
I am having issues finding where the air is getting in on a 2012 Mack CXU613 MP8. Any tips or advice?
