Hello, I had my pump and injectors rebuilt about a year and a half ago and have been experiencing a weird problem as of just the other day. When accelerating with the smallest amount of throttle I can it will all of a sudden give itself what feels like over half throttle. I suspect that I have a fuel leak as the other day diesel was dripping from the frame. Could erratic fuel pressure cause suck a problem? Also when the truck is on high idle it revs like crazy as that is the same throttle position that give a problem.

Air leak somewhere, leaks fuel when not running, sucks air when running. If the fuel showed up on the frame, start there. Cracked hoses near the dual tank switch-over valve was quite common, due to exhaust heat and sharp bends.

Well an inspection found no leaks. Must have had a tank filled to the top leaking out. Now what can I try? I have an electric lift pump.

does sound like air becuse if air gets in the ip the ip will advance? the timing and it makes it feel more powerful

i guess the next step is pressurize the tanks?

yea you could take off the return line from the ip and put around 2psi presure and listen for noise if theres no noise on one tank change them over and see if the other one leaks

Replace the return line at the IP with a clear hose and look for bubbles indicating air in lines. That gives the problem you have.

Other than that, worn advance in the IP does it.

I have the same problem with air getting in on my diesel side,i replaced the electric lift pump.I have clear lines from the lift pump to my 6 way valve.I can see bubbles comming out of the pump so the air must be comming from the tank or the rubber pipes on top of the tank.Could the diesel return being clogged cause this?It runs great on WVO,i have a seperate tank and pump for the WVO.

Fixed! Turns out when I checked the lines I only checked the steel ones. The rubber line on the suction side of the electric lift pump had a crack and pin hole in it. Went for a 50 mile cruise last night and it working like new again. Thanks again for the help.

that great! always good to hear about a good running 6.2

I checked the diesel return line,its clear and is flowing into the tank.Im still getting lots of air bubbles comming out of the electric lift pump.I guess tomorrow im going to drop the diesel fuel tank.Theres steel lines that go to rubber then back to steel,so maybe theres a small pin hole in the rubber line somewhere.or maybe the worthless sock on the fuel pickup is clogged,if so i will remove and discard.