My truck has had a rough idle when the engine is warm latley. After getting off the interstate it shakes a little more than usual. I replaced the fuel filter and no change. Has anyone had issues with their ICP or IPR, also where are they located and how hard to remove? Any instructions or tips on how to smooth out the idle?

 

I have a 95 that would idle really rough. I also had a bad flywheel. when i replaced the flywheel to a solidmass from dualmass my idle problem went away. I never even considered that my flywheel was causing my idle problem too. So if you have a manual transmission and are having some vibration issues you might need to check there. on the 95's it is simple to check now that i know what to look for. This is how i would check it.
remove the dust cover so you can see the flywheel and pressure plate, on the engine side of the flywheel there are some springs you should be able to see two at a time fairly easy and you want to look for broken ends on these and inside the springs there are some weights and you want to check these for broken pieces also. next thing i would check would be for slack in the flywheel. do this by putting the transmission in neutral then try to turn the pressure plate if you get much movement this might be your problem. again this is only my experience with my truck and i could be wrong. hopefully some of the more experienced psd guys will be able to confirm my theory.

 

if im not mistaking the two rotational masses should have no more than 3/4 inch of play for the clutch.

are you sure your firing on all 8 injectors? sounds like you may have some burnt wiring or non working injectors.

 

I replaced the dual mass to a single mass flywheel from south bend. My programer doesnt give me any codes telling me the injectors are bad but.... I have never replaced them and it has 220,000 miles on the stock injectors. Would the scanner pick up anything for a burnt wire harness? So could the ICP and IPR be giving me this rough idle, or is it the costly route of injectors? Again it only does it when the engine is hot. Any ideas?

 

I have a 95 with auto trans. It also idles rouger after it warms up and the idle fluctuates a little also. I'm considering replacing o-rings on the IPR. The IPC is located on the driver's side head at the front and top of the head. The IPR is located under the HPOP. Some of the guy's I know that have these engines also talk about rough idling. Hope this helps.

 

Mine does a similar thing. But on fresh oil its smooth. How long since a oil change?? You may consider trying a different oil?? I just switched from delo to a Exxon/mobile 15-40w oil. So far I really like it. We'll have to see how it holds up after a few thousand miles. But fresh oil is night and day difference with my truck as far as smoothness and performance.

 

I am running delo 15-40 and it has about 2500 miles on it. This engine has seen nothing else but delo in it since we got it in 96. Would it be worth it to change to a synthetic with >200,000 miles? Changing o rings in the IPR, is this a pain to do? Also you guys got me to wonder about my injectors, aprox. how long should they last?

 

I guess my question is how rough is rough. WHen my trucks run rough, sometimes its after too much town driving and idling. I put in some Stanadyne and make a highway run. After that its back to smooth idling.

I just try the easy stuff first then move down the list.

 

It is not a really rough idle. The only way I can explain it is, its kinda like a gas engine with a high lift cam. I have used diesel kleen before but its been a few months since I have put any in.

 

Mine is doing the same thing, only when at full operating temp also my oil is fresh.

If it was the wires or an injector why would it only do it when warm?

Is it because more fuel or the idle is higher when cold?

 

I was almost forced into getting some new stage I's but it sounds like this is a common issue with these engines.
BLTFordTough how many miles do you have on yours?

 

Mine does the same thing but only when you run it real hard then the next couple of idles I stop it lobes up and down I have 180,000 miles as a reference with all original Injectors won't be long till I get bigger though. I read on baz's site that he had the same problem and replaced the IPR and it seemed to fix his problem but I have never tryed it yet.

 

I noticed that just driving in town the idle will fluctuate. It will stay down @ ~600rpm then creap up ~50 rpms and work its way back down to 600 then shake and go back up ~50, and it keeps doing this when the engine is warm. I think this is where my rough idle is comming from. What causes these symptoms? I might be a little picky about how smooth it runs but I have predicted two powerstrokes, of guys I know, breaking down by how they idle. One the harness was burnt and the other was a dual mass clutch. Any ideas?

 

That sounds like enough to look into. Ive never had mine vary (once warm) by more than 5 rpms.

 

you guys need to get a cylinder contribution test done. when you accelerate is it choppy going through the turbo? i was running on 5 cylinders and only 140,000 miles.