Asking for my Uncle. 01 3500 4x4 6spd

Was having issues with missing and thought it was the fuel filter, eventually went to no start. Called me for help. Not getting any fuel. Found an aftermarket Carter fuel pump (frame mounted) that had gone bad. Replaced and now its pumping good. Starts and idles just fine.

Now the strange issue. It has no power. Might hit 1500 rpms if lucky. Can barely hold speed on its own.

The stranger issue, its intermittent. Some times it will run fine, other times not. One quirk discovered is that if it starts running powerless, if you hit the clutch, flick the ignition off and then start back up it will fun fine for 8 to 10 seconds and then back to powerless.

NO CODES. Its been put on a diagnostic reader at a local mechanic and it shows nothing to be out (ie apps) He has only had the truck about 3 months. 130k miles or so. Previous owner said he had changed the injector pump within the last 10k miles.

Any ideas what could be going on.

I appreciate the help.

Blake

 

If it was me I would ensure that you do actually have fuel pressure all the time, if it doesn't have a fuel pressure gauge it should. A new pump doesn't mean it's good. As it's intermittent I would suspect electrical and not something like a fuel filter. As a last resort when a computer won't fault anything it's either something the computer doesn't monitor or it's the computer.

 

Might try swapping out the horn relay and injection pump relay in the under hood fuse box. I don't believe that would cause the symptoms you describe, but it's free and worth a try. That's similar to what happened when my relay crapped out.

 

Ive had carter pumps run, appear to put out good pressure, but the gauge was showing only 2psi.
That was on two new carter fuel pumps.

 

Thanks for the advice fellas, Ill pass it along.

 

Sounds like timing failure in the vp44.

No codes makes me think ecm, it should be throwing something, though.

 

Hey Blake, is it puffing any coloured smoke when its low on power, such as blue, when it won't go past 1500?

 

Sure does, was following dad in it the other day and it would puff blue smoke on occasion, start running ok, then back to sluggish.

 

what you have happening, is a mechanical failure of the timing piston in its bore. It'll catch, while under pressure, and not allow the timing to advance or retard as required. Take the pressure away, even momentarily, and it happies up for a while.

Please note, this is a Mechanical failure. Most times it is NOT accompanied by a code. Which leaves most people guessing. I have been through this with several trucks, and each time, you diagnose. Check all wiring connections, batteries, power is good, grounds are good, and still the problem.

This happens on units that spend a lot of time at one throttle setting, such as highway driving at a constant speed. This can also wear a dead spot in the APPS.

That said, I have done hard resets on the APPS, and even changed them, trying to rectify what you are experiencing, and no luck at all. Now the APPS will not always throw a code either. Weird, but true. it will cause all worlds of grief, but you'll have to sit there with the key on, engine running, and play with the throttle pedal until you hit that dead spot, and it decides to throw a check engine light.

Back to the pump though, the reason for my diagnosis is the fact that it is intermittent, where the apps would have a stumble in the exact same spot every time.


My 01 is starting to do this exact thing on occasion, so I have yet another VP pump sitting on the shelf waiting. It gets to me, as this thing is fed air free, triple filtered fuel at 18psi all the time, with low ash two cycle oil as a lubricity additive. This pump has almost 40,000km on it. I have had one reman that made 862km.

Good luck with it.

 

Bro Pind

You hit that one right on the head. New injector pump and all is well.

Thanks Fellas

Blake

 

Bites having to drop the money on a new pump, but always nice having it running right again.

 

Bro Blake.

Good to hear you got it working right. Sucks about the pump, but such is the nature of the beast.

I'll still put up with my bad VP44 pumps, over the bad injectors, fca's cp3s etc on the newer trucks.

Actually, in light of what I have seen for problems on the newer trucks in general, I think I'll stick with the 2nd gens.

Take it easy