Engine/Transmission (1994 - 1998) Another fuel problem?

[Morgante]

Engine starting and power normal. Minimal smoke. The problem is at times the engine will first emit a ticking noise, then the engine will remain at given RPM even when throttle is released(no power at this point). Then often times it will die. The unit can be restarted immediately. It will do this under load or by running out of gear at near full throttle. The truck has 2 tanks switched with electric valve, both vented properly. 3/8" lines has new liftpump, clean screen, new overflow valve, checked lift pump presssure(in spec), new filter. Bypassed tank valve and ran tanks seperatly. Bypassed whole fuel system and ran engine off jug of fuel both supply and return. Run selenoid operating properly. Put stethescope on P7100 pump when making ticking sound. Noise is in the pump.



Is it the pump? Can pump be repaired or do I have to just buy a rebuild? This unit has always ran great with no problems in the past.



It is a 94' 12V with 104K miles in a 79 ford F-350 5spd that hauls 20K lbs of scrap metal. The engine is stock.

 

[JFaughn]

Has this just started happening , or after this installed in Ford ?
Whats the history of eng/pump ?
Some pump mods with some thing undone /lose ?
What area are you in , maybe someone can look at it with you ?

 

[Morgante]

It has been in the ford hauling huge loads for a while before this started happening. The eng/pump is stock owned by a guy who towed a small trailer with no problems before I picked it up. There aren't any mods or anything. I have a good bit of experience with diesels. I just haven't ever seen anything like this. Thanks for the reply.

 

[Joe G.]

The tick is because of the way the lift pump works. The push rod compresses a spring. The spring is what moves the fuel. If the spring can't keep up with the push rod for some reason (dirty fuel filter or ???) there will be a little slack so you get a ticking sound. If there is an air leak in the fuel lines coming from the tanks, it can also cause this. As long as you have good fuel pressure and it runs good it should not be a problem.

 

[CTD12V]

The problem is at times the engine will first emit a ticking noise, then the engine will remain at given RPM even when throttle is released(no power at this point). Then often times it will die. The unit can be restarted immediately. It will do this under load or by running out of gear at near full throttle.

Almost sounds like a governor spring problem? I don't know enough about the gov spings to help you much, but hopefully someone else can say whether or not a broken spring or something would cause the RPMs to stick, then die. Is your throttle linkage binding? I think there was a recall for some of those older years because the throttle cable would fray and cause a "runaway" condition (not a true runaway like you get with a leaking turbo). The ticking sound may be independant of the RPM problem. Does it always tick, or only when you have the problem you described?



CTD12V

 

[DPashko]

Try some diesel conditioner, preferably Standyne. Mine ticks once in a while if I dont run the conditioner. Maybe a lack of lubrication with the new low sulphur junk.

 

[Morgante]

Almost sounds like a governor spring problem? I don't know enough about the gov spings to help you much, but hopefully someone else can say whether or not a broken spring or something would cause the RPMs to stick, then die. Is your throttle linkage binding? I think there was a recall for some of those older years because the throttle cable would fray and cause a "runaway" condition (not a true runaway like you get with a leaking turbo). The ticking sound may be independant of the RPM problem. Does it always tick, or only when you have the problem you described?



CTD12V

The throttle linkage is fine. It only ticks right before it dies.

 

[tgordon]

I am by no means a pump expert, but sounds like CTD12V is in the right area. If the engine will start right back up immediatly after dieing and act normal and not sluggish as you said I think the lift pump is fine. Might want to get it checked out, had a tractor on the farm start to over rev when put under load and after I hit over 3,000 rpm on an engine designed for 2500 with the throttle in a position where it should have been about 1000, it got pulled to be rebuilt. I would hate to hear of your engine blowing up, not that I know if it will or not from this.



You can look into it, but the last pump I sent in to get rebuilt was cheaper to exchange than it was going to be to rebuild it, but this will vary be what is wrong, and depend upon how fast you want to get the truck back on the road.