Cummins missing.

Walter Buller · May 11, 2012

If a 1993 12v 5.9 Cummins with about 350K on it runs like it has a miss, i.e., runs rough, no power, sluggish, what might be the problem? We have changed the fuel filters, rebuilt the pump, including a new solenoid, tested the injectors, which were working perfectly, each one popping at 3600#, put a good additive in the fuel, and scratched our heads with one hand and our butts with the other one. It still does it. Any ideas?

puln70 · May 12, 2012

I didn't see aything about adjusting valves?

Walter Buller · May 12, 2012

We did that too.

Lyndon - AB · May 12, 2012

Lift pump broken or partially plugged?

Not very experienced with the dodge's, but had a delimber that had similar symptoms. Turned out to be a mostly plugged inlet line to the lift pump. Let just enough fuel through to run, but no power, stumbling, etc. Had to steam all the dust and crap out of the fuel tank.

Another possibility is air entering the fuel stream. If you put a clear line in between the filters and the injector pump, you can see if there are any air bubbles in the fuel stream.

Hope that gives you a few things to go on.

Lyndon

alvan · May 12, 2012

I had a 8.3 cummins that done the same thang and it turned out to be the lift pump the screen going in to the pump was stopped up witch made the pump to pump air put a new lift pump on and cleaned the tank now runs like a top
easy and cheep fix hope this is your problem.

Kip-Utah · May 14, 2012

If it's missing have you notified the authorities?!!! LOL Kip

Walter Buller · May 14, 2012

Actually, I discovered the problem this morning. I disconnected the fuel lines from the first three injectors, and connected them to good, spare injectors I had. I had my wife crank the motor while I watched. Number 3 injector was not putting out any fuel at all. I swapped this injector with another good one, with the same result. The problem is the newly rebuilt pump.

phil25 · May 14, 2012

not sure if this applies or not, but the air intake is clean?, if it has turbo, any chance the turbo inlet/outlet vanes are stuck/restricted?
in my case there was a non-operating intake vane, setting the fault code ,and sending a stop engine signal= runs clean, but no power, sluggish,slightly, any chance that it is down on coolant? the rad level sensor will set a stop engine code also.
just throwing it out there

Walter Buller · May 14, 2012

See my previous answer.

scotc · May 28, 2012

Definitely the pump, they missed something, or didn't go into it as far as they would have you believe. If it was a fuel supply issue it wouldn't be firing good on certain ones and then not on certain others.
good place for info on your truck

Cummins missing.

Walter Buller

Member

puln70

Member

Walter Buller

Member

Lyndon - AB

Member

alvan

Member

Kip-Utah

Member

Walter Buller

Member

phil25

Member

Walter Buller

Member

scotc

Well-known Member

Similar threads