Hi. Just got my first Cummins. Love it. Problem is the fuel gauge is out of whack and I ran her dry. Dumped some more fuel in and she ran like crap. I limped her home, keeping a VERY close eye on the gauges.
Changed the fuel filter. Still no power. Started checking around. Found out about bleeding the lines and what not. Went back and redid the fuel filter the right way. Still no power.
Cracked the injectors to bleed the lines. Still no power. Truck was throwing a code for a bad crank trigger. Replaced that. No change.
She lopes pretty bad on a cold start. She'll run half good for about 30 seconds on a warm start and then settle into a rough idle. No smoke of any color. Every now and then she'll catch for a second or to and then right back to a rough idle.
If she was a gas engine I blame spark advance (or lack of advance) Cause that's what it acts like. I've been working on gas engines for years. Diesels are brand new to me and as I'm finding out a different animal. Any ideas or pointers in the right direction would be appreciated. Thanks in advance.

 

Is this a 98-02 24v? I'm guessing it is if you're bleeding lines...

Your pump might be done. The VP doesn't tolerate no lubrication very well. A pump usually throws a code and has a dead pedal (runs but has little response to pedal input).

 

The truck is an 05. Put the scanner on it this morning. Throwing P0204 (#4 injector circuit open), P0335, P0336, (crank sensor) and P2149 (Fuel injector grp B supply voltage circuit open). Just for laughs I pulled the harness on the crank sensor, made zero difference in the way the she ran. Just put the sensor itself in yesterday. So I'm thinking wiring or PCM, Electrical gremlins are the worst. Just wondering if anybody has had similar problems and what it took to fix it.

 

Good lord man. Don't EVER crack the injection lines on a Common Rail. For one it will do absolutely nothing for you, as it needs to maintain rail pressure or it'll never run right, and for two, that system is capable of pushing 23,000psi; it's dangerous. The system is 100% self bleeding.

The injector wiring harness is known to short, and it does trip a code for a circuit being open. So, I would pop the valvecover (on an 05, you have the plastic valvecover cover on top of the actual valvecover) and do a visual inspection. It's 6 10mm bolts IIRC.

 

LOL Dodged a bullet with cracking the lines. Found out what type of pressure was involved after the fact.
Valve cover is off. Nothing is obviously out of sorts. Probably should check the resistance on the #4 injector. Maybe continuity on the harness where it passes through the head.