running rough

[meat_fire]

Truck not running right, it has a rough idle, and is very rough around 30 to 40 mph range. It seems to smooth out around 50 and ok above 50. It has some power but not like it should, I have switched tanks and diesel is from different station on front VS back tank. I have added standayne and Lucas to both tanks, did not seem to help any.

I have changed fuel filter, and cleaned the screen., screen was pretty dirty. It seems to run ok sometimes but most of time it is running real rough. I also changed out CPS and still the same

Another thing happen today is my gauge for the PYRO started acting crazy, one second it be showing 800 at 60 MPH then next it be at 0 then jump around to 400. I ran it about 15 miles with it on 0 then all of a sudden it jumped back to 800.Doubt this would be related, but it started acting up about the same time truck did.
Any ideas or suggestions would be appreciated
Thanks

 

[wanderer]

sounds like clogged injector nozzles to me. Do you have white smoke at idle? If so, those little holes in the injectors won't be cleaned with injector cleaner. Easy enough to pull them, and take them to someone who can take them apart and clean them properly.

 

[Mike]

CEL on or not? If you have a CEL on, do you have the ability to pull the codes? It does sound like a fuel delivery problem. Can you check the fuel pressure at the schreader valve?

 

[Big Red CC Dually]

I agree with Mike (95_stroker) on a fuel delivery problem, perhaps the fuel pump is short for this world. You should have minimum of 40 psi fuel pressure at idle. If you were to install a test gage with a hose to enable reading outside the engine bay while driving, it would verify if the pump was weak during operation at the speeds you mentioned in your post.

 

[meat_fire]

Thanks for the replies.
Checked the fuel pressure, it running about 52 at idle. No smoke at idle, only smoke is at start or when I hit it pretty hard.
It seems to take periods of running decent then running rough. I was hauling load of fertilzer yesterday (about 5 tons ). and it would ok till a hill then it would shake and run real rough. But if i got on it it seemed to run ok, just seemed to be lacking some of normal power it use to have.
One question is when i did change the CPS I did not disconnect the batteries. Someone told me that I need to disconnect or take out the #9 fuse. i did taKe out the #9 after i had change cps and run the truck for few minutes. I left #9 out all night, but could not see no change after i put fuse back in.
Also too oil filler cap off and could not smell any burnt smell like a burnt wiring harness.

 

[Bean]

Sounds pretty much like an injetcor problem, possibly scored plungers. f it shakes at idle then you can unplug the connectors at teh vc's and rock them back and forth to cut out each injector, which ever one makes the least difference is your culprit.

 

[meat_fire]

Just had it run on computer came back with a 1298 code. They say that is the IDM and it also showing one bad injector (#4). Is there any option to replace IDM or somewhere to get one cheaper, I just called IH dealer and they want 845.00 for it. There is no CEL being thrown.

I have heard that the usually when the IDM goes out the truck will not run. Mine is still running, just rough like running on 7 instead of 8.I actually hauled some cattle with it last weekend, it pulled them fair but not the normal power.
Hate to spend 1000 dollars on it and not get what is wrong fixed or replace something that is not needed.
Thanks for all the help and suggestions