Power Fluctuating At Speed

[Josh]

This has been happening with my deuce for a while now. Some times it will be run down the freeway at 55mph with hardly any petal, and some days on the same stretch of road, I Have to keep the truck pinned to maintain 50-55. This happened before and after I replaced my fuelfilters. Just to be on the safe side I had a diesel shop thats done lots of work for me on other rigs change the filters again and it didn't make a differance.

I run a blend of just about everything in this, and just to see if it was my oil/gas/diesel mix, I drained the fuel take and filled with clean diesel, swaped the filters again, and bled the lines. Still same thing, Intermitent power followed by gutlessness.

To give a good example, near my house there is a 9% grade for about 3 blocks to get down to a boat ramp, I normally end up driving up on my way home because some urban wheeling roads, end down there. Some days I can pull the hill in 4th LO with it @ 20mph, Other days its wont pull the hill in 4th and I need to downshift to 3rd. Always hit the hill @ 22 in 4th lo.

Ambeint temps are where all with in 50-70degs.

I know the intake pump is working, I think I had 12psi @ the secondaries.(been a month or 2 since I checked).

Im starting to think its a bad HH, but I also noticed one of my injector lines is starting to leak right at the pump, Its a very mild leak, After about 20 minutes of driving, I parked the truck and with in an hour there was about 5-6 drops on the gound, Could this tiny leak be causing this problem? Either way I'm ordering a new set of injector lines and am debating if I should order a HH while I'm at it.

Anyone else had this problem?

Thanks in advance.

 

[bratpackdad]

Hmmm...I vote for air getting in via a leak. I think you're on the right track with new lines go the extra mile with a new HH. I'm sure someone else will have a cheaper idea.

 

[dittle]

This may be way out there but if your FDC isn't bypassed I wonder if it is going bad causing the major power fluctuations. That is the purpose of the FDC in the first place.....adjust power based of fuel viscosity.

 

[Jimma]

That sounds reasonable being that he is running various fuels.

 

[Wildchild467]

would dirty injectors have anything to do with it? how many miles are on the truck? maybe running various fuels has some crud built up on the injectors? Maybe try measuring the temperature of each cylinder somehow to see if there is much of a difference...possibly at an injector? Does your truck idle smooth?

 

[armadillofz1]

i have the same exact problem. i posted a thread about it a while back. still no solutions

 

[Wildchild467]

My truck seems to "hunt" sometimes at idle speed....it'll rev up and down so very slightly, i dont even think i can see it in the tachometer. I heard high compression diesels like ours have a habbit of doing that.... not sure. it didnt always do that though, so im not sure. Anyway, you may want to check all of your fuel lines. my air compressor gasket was leaking (i changed that last night) and canister oil filters leak so it makes it hard to see any fuel leaks by the IP if there were any. Tonight i will be changing my oil and filters to the jatonka spin ons, so i wont have any leaks then. It should make it easier to find a fuel leak if i have one.