PeachParts Mercedes-Benz Forum - View Single Post - primer pump only pushes air- how to purge air from diesel generator?

bigblue · #1 10-18-2009, 02:45 PM

I apologize for this being a non-mercedes specific diesel tech question, but I am a somewhat regular on this forum and know there are plenty of well educated individuals who could help me with my issue. I am having fuel starvation problems, after hours of continous running it will randomly start to bog down and then stall.

i have an older non-idi diesel generator. It has a mitsubishi 4cyl turbo engine from 1980's vintage Mitsubishi canter (australian truck) engine. It has 2 screw on fuel filters and a primer hand pump on the injection pump.

When this happens and I try to re-prime it, usually the hand pump doesn't feel to have any resistence which is telling it is only pushing air into the injection pump. i immediately replaced the hand primer with a new bosch spare (for my 617 mercedes) hoping it was the issue. So I figured to post a question here since this engine shares at least a few common components with our mercedes diesels.

I think gravity might be my culprit. My fuel tank is about 4 feet below the primer pump (as well as the rest of the engine) and the only way I have ever had any sucess it to loosen the hand primer, and rig up a setup to pressurize my fuel tank until I notice fuel coming from the hand primer, quickly tighten it, and pump, which is not easy to do. My fuel hoses are a little old but seem to be intact. I'll replace them.

Does this make any sense or am I way off? Can anybody suggest a solution? I don't have too much experience with diesel generators, or anything non-automotive. My business depends on reliable operation of this generator.