Random Engine Power Cut In/Out

[JGrefenstette]

been a while fellas, sorry to be a stranger. between taking diesel classes all day and wrenching for a trucking company all night, my 80+ hours a week have left me with little time for the online side of things.



my question is this: today just after filling up, aftr about 15miles of driving on the fresh tank actually, i was cruising in 5th, 65mph, 1800rpm, and i felt the engine studder on me. it was like the fuel was cut then almost instantly came back. almost as if your at highway speed, and for a split second, remove voltage from the fuel shut off solenoid then apply voltage almost imidiatly again, and the speed of the engines carrys on the whole time with just a slight sign of a momentary fuel loss. does that make any sense at all?



my first thought, the truck stop ive fuelled at for months, ive herd from one guy witha powerstroke, that he got bad fuel and his truck almost wouldnt run.

so i begin to wonder if its water in the fuel, or some kind of contaminant. my fuel filter only has about 4k miles on it. i drain it regularly. and run stanadyne performance in every tank. have since i bought the truck.



does this sound like a problem with the fuel it self, or more along the lines of fuel delivery, lift pump, VE, injectors.



ive only flelt this twice, and it was cruising on level ground at highway speed, no load, throttle position steady, 700-800 egt, 6-8 psi boost. only happend since this last tank.



thanks yall, good to be back in the nut house. its been too long

 

[MMiller]

I'd be more leaning twords the connections on the shut off solenoid. I've had to replace the ends on my wiring at the shut off solenoid to stop that problem. A plugged fuel filter will not usually be intermintant.



Michael

 

[Bob Beauchaine]

I second the shut off - been there done that.



Bob

 

[Tippin Spotted Cow]

Lift pump maybe? I don't think the solenoid can cut power while the engine is wound up. Try stabbing the pedal and shutting off the truck and the same time. The motor will wind down as if the key was still "on" then kill out when it gets down closer to idle.

 

[DieselBuzz]

I've pulled over a couple of times and shoved that little connection so it's tight again. I replaced the end last year and haven't had any trouble since.

Try idling the truck in the driveway and then just tug on the wire a bit, see if that makes it stumble. It's a easier fix than a lift or injection pump. Good luck with it.

 

[bmoeller]

Have you changed the fuel filter? IDK if the 1st gen also has a fuel pre-screen under the fuel heater that could be dirty?

 

[JLEONARD]

I tend more to think fuel delivery. . NOT the solenoid.

Filter, lift pump, etc.

Been there too many times. Rarely the solenoid... rarley.

 

[JGrefenstette]

so i begin to wonder if its water in the fuel, or some kind of contaminant. my fuel filter only has about 4k miles on it. i drain it regularly. and run stanadyne performance in every tank. have since i bought the truck.

i agree with you JLeonard, im thinkin more along the lines of the fuel deliver, more so the fuel it self. cause its just to coincidental for it to start for the first time ever, one a few miles after this fillup. and even though i run quality Fleetgaurd filters, their efficiency still alows some contaminants to pass, their not perfect. i will check the connection of the solenoid. im gonna run this tank out, then start fuelling elsewhere. shouldnt be to hard to burn up this fuel, ive been foolin with the old VE, so i can drain a tank of fuel a little easier these days. :-laf

 

[9312valve]

After adjusting my full power screw when i first beganmessing with my pump i had bumped the shut off solenoid connections down. Well anyway I got in the truck started fine and went off down the roadand hit the throttle the truck studdered and died. After throwing lots of adjectives at the truck, i popped the hood to see the endshad shorted out on the pump and shut down truck, replaced ends and wrapped them in electrical tape haven't had a problem. Just a thought.

 

[waltk]

Its really hard to kill the fuel supply parts in the 1st gen trucks. Mine spent much of its life as a tuned-up truck-pulling tuck, and I have yet to see any signs of pump failure, life or engine. Like was said earlier, solinoid is cheaper than a pump.

 

[MEby]

I wouldn't bother getting a new solenoid just yet. Pull the old one out for a coulple days and put the nut back on to see if that really is the problem.

 

[JGrefenstette]

well fellas, ive come to the conclusion that it was simply some bad fuel at the bottom of my tank, that was sucked up. i checked the solenoid. conection is fine. i just drove the truck yesterday on an 1 1/2 hour trip to Rockingham Speedway for Mopars @ the Rock, and i rode the old cummins harder than i ever have before, and ive never been so impressed. i got less than half a tank left, im gonna run it out, then start fuelling elsewhere from now on. hope that does the trick for me. thanks for all the input guys.

oh yea, there was a 1st gen there, that was runin 12. 25 in the quater. ill try an get pictures of it. nice truck. thanks again yall.