Running rough?

[lmorgan]

My son has a '95 7.3L PSD and we've had few problems with it overall. He called from college the other day to tell me that the truck was running really rough and was missing and he couldn't get any speed. He pulled into a K-mart, killed the truck, started it back and it ran fine for a few minutes then started doing it again. I trailered the truck home and ran it a few times around here. Mostly it ran fine, but several times it did run really rough and I could detect a dead miss and rough idle. I assumed it may be the FICM, but decided to pull codes instead. My Snap-On scanner with the KOEO mode pulled only one code: P1111 System Pass. I pulled the memory codes and pulled a P1282 excessive ICP and a 1211 ICP pressure above/below normal. The FICM had been replaced years ago and I replaced the IPR as well, so I assume these codes may go back to there. Regardless, I cleared the codes and did both an KOEO and a KEOR test and pulled no code except the P1111 System Pass.

What is a P1111 anyway? Could it be that my problem may be something simple like bad diesel or dirty filters?

[lmorgan]

Does anyone know what a P1111 is?

[swaan]

Check your fuel presure first. Shrader valve on the filter , should be 50-60 psi.

Your mechanical fuel pump in the valley of the engine could of just taken a dump. Same thing just happened to my 97.

[lmorgan]

Thanks! When your fuel pump went south, did you have a rough idle/run all the time or intermittenly? Sometimes this one will run great for awhile, then crap out on me.

[jesilvas]

Can be fuel pressure, can be high pressure oil, can be UVCHs, maybe even CPS but doubtful that's it.

[lmorgan]

Wouldn't the CPS, UVCH, and the HPOP all throw codes if they were bad?

[swaan]

Originally Posted by lmorgan

Thanks! When your fuel pump went south, did you have a rough idle/run all the time or intermittenly? Sometimes this one will run great for awhile, then crap out on me.

Yup, ran fine then when the demand for lots of fuel was there it would suck the filter housing dry then run really bad miss shake. If you let it idle it would catch up to it self then start running fine. But it just got worse and worse to the point I almost had to be towed home. New pump and she goes like a raped ape!!

[jesilvas]

You'd hope they'd throw codes, and usually will, yes.

[SoCalPwrStrk]

My truck did the same thing, it would run fine then start missing then wouldnt start at all, turned out to be the electrical connector to the IPR, i was getting the P1211 when trying to start.