I'm new to this forum, but I've had this truck since 1999. I originally got this truck to transport 5th wheel, travel trailers, and boats for delivery. I've towed things all over the country, and could climb 6% grades like ashland hill on I-5 at between 45-50 mph with everything but the heaviest 5th wheel. Getting an average mpg of 13-14. For the past 8 years I don't drive much except to get wood, haul the dirt bike, or pull my travel trailer that weights fully loaded 7600 lbs. Unloaded the truck now gets 10-12 mpg highway at a conservative 55-60 mph. Pulling my trailer I get 8 mpg. and climbing the truck can only muster 30-35 mph on a 6%. Right at that spot where it's either wound out or lugging. truck has 3.73 rear end with duallies.

last year, which I haven't driven a 1000 miles since. I had some $2000 worth of repairs done. the oil unit that's at the top of the motor in front of the fuel bowl was replaced, glow plugs. I came to the mechanic with these same complaints, of low power poor fuel economy I know he did what he needed to do as far as repairs that needed to be done, and that I could afford at the time. I walked away hoping that the problem was solved. Though the truck runs smoother, it still has low power and poor mpg. Later trucks have a ficm that can with low voltage give similar troubles. But my truck doesn't have one at least not one that I can find. Tires are inflated, that metal tube that runs down the front of the motor was cleaned out with the sensor checked by the mechanic. When it comes to diesel I'm a complete noob. My gas powered cars I usually have no trouble working on them. But this truck is a bit over my head in the mechanical arena. And I would like to hear some suggestions from some more experienced folks on what could be causing me this trouble. Any help would be appreciated.

 

You have a IDM .... FICM are in the 6.0 engines ( totally different )
IF you have the Stock setup ..consider these simple conditions/ Questions.....

1. What is your fuel pressure
2. Do you have any exhaust leaks ( look for soot )
3. What is your Boost ( related to soot stains )
4. How many miles on Injectors
5. Are there any codes present ( You need a Good Scanner for this )
6. Do you have a CAT

 

When was the last time the filter was changed? How many miles are on the truck? These are a great group of guys that will get it figured out.

 

Specifically long hair, short or Siamese?

 

Well as EVERYBODY knows I prefer the 7.2...But I am rerfering to the SOOT trap after the downpipe / Before the muffler.... in this case.....

PS : I am Also a Mason....the real kind and the Tribal one as well...

 

I have found several traveling brothers on this forum.

 

Well I'm more of the Prodigal Son / Templars /Hospitaliers / type of Brother ...( Jesuit educated ) Like ......If the Holy Father was a Guard/ Centre in NFL ...before he was a Cardinal....

 

Subscribed

I m getting **** pore milage too
All this starred after I tore truck down and made it a dually and added I/C
NO, brakes are not dragging, I can spin axle by hand)

So far in attempt to correct…..

rebuilt turbo and added WW2 and did away with EBPV
fixed boost leaks(I/C hoses, tunes, Intakes, up-pipes)
Installed Irate up-pipes(leaking)
T500 HPOP(thawing cel)
1.0 exhaust housingJust while I was there)
HPOP to head hoses(leaking)
Fuel lined from frame to fuel pump & housing &bb mod. (Seaping)
new fuel pump(leaking)
New VC gaskets, UVCH, & 8 GPS(throwing code for one bank and hard starts)
EBP sensor and tube(just because)

towing I see about 7mpg and driving around I am lucky to get 10

All this starred after I tore truck down and made it a dually and added I/C

 

Could it be the injectors are failing Brad?

 

If you mean you are throwing the cel code under load ? you could have a weak / wornout lPOP.....can you measure it with a have mechanical guage ..I think the port on the Turbo pedestal is the direct Lpop pressure...

 

Filters are good, brakes don't drag. All the epa suggestion are good. Like I said the mechanic that worked on it last went from the bottom up. From easiest to where I couldn't afford to go any further which was the oil compressor. not sure what it's called but supplies oil pressure to the injectors. Got that fixed. it was leaking oil down the valley. How do you check for failing injectors? The truck has 189,000 Thanks doug for the reply.

 

1. I don't know I'll have to check it. how do I check it and what pressure am I looking for?
2. no
3. I don't know how to check it without a boost controller, but I do have a intake leak tester. I check that out
4. same as the truck 189k
5. not that show up on the dash. no idiot lights flash, so do I need a scanner to dig deeper?
6. Yes I do have a cat. As a matter of fact the entire exhaust without leaks I will ad is stock.

 

1. You check it at the Shreader Valve ( looks like a VALVE Stem )on drivers side of the Filterbowl assembly part of the FPR it should be around 20 psi cranking...50-65 psi under load...
3. you need a Mechanical Boost guage or a good scanner that can read the MAP sensor
5. Yes
6. Get rid of the CAT first .... and then maybe upgrade the downpipe...

 

That's great info... Thank you very much. I 'll do those things and let you know what I find.