92smokin blacky

When I put the pedal to the floor for a lil while in my truck and let off, sometimes it will start sputtering and popping like im running out of fuel or I have air in the in the fuel system. Usually rrompin on it a bit or keepin it running will clean it back up and get it running smooth again when it does this. I know while truck pulling I would romp on the throttle a few times at the end of a pull to clean it out and keep the motor running. And I try to do the same on the street to clean it out cuz im sure its the same concept but it only does this sometimes and its weird it still does it when it is usually a much shorter hard pull on the street than pulling.

My buddy explained to me what caused this and why ya clean it out after a hard pull. He told me that you start sending your injectors all that fuel then when ya let off, all that fuel now goes through your return line rather the injector causing it to act like it ran out of fuel or is not getting enough. Is this the right theory? It makes sense in my head but today I got on it just for a few seconds and let off and my truck died in the road, I cranked it a few times then it fired back up and was ratty for a lil bit then was fine. Im just kinda curious what exactly causes this and what you other guys do? I just try to romp on it a
little when i let off or let off slower but I usually forget. but is this a normal occuring thing or do I have some other problem? I've got an Airdog II 200gph and custom sump set to 14 psi and probably goes down to 12 at WOT, so I don't think fuel supply is a problem.

BearKiller

My guess is that you have a pump-timing issue, most likely a bit retarded, but too high in time will also cause it.

A properly tuned diesel does not need to be babied and "cleaned out", regardless of advice to the contrary.

Something ain't quite right or else it would perform smoothly.

Onemoparnut

Mine does the same thing if I don't let off easy. I was told that it is because the presure in the cylinder goes higher than the pressure in the injector for a second when you let off quickly. So it pushes air back into the injectors and it runs crappy till it gets the air out.

BC847

^^This.

Learn to roll off the throttle instead of side-stepping it.

92smokin blacky

That makes sense especially since im runnin a lot more boost with this bigger turbo. It never seemed to do this with smaller turbos and less boost. So I guess lettin off easy is pretty much the only way around it? Thanks for the help, it makes more sense now.

Ive got my timing jumped a tooth and its running good so I wouldn't think it would be that especially when im not the only one runnin a lot of timing.

The_Head

Wasn't "snoot" having this problem on his compound turbo setup? He would boost a certain amount and it would kill the motor?

JQmile

Mine was doing the same thing. Stopped lifting off the loud pedal suddenly and it stopped. Don't care why, it just works