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Does anybody have any ideas. My 99 350 PSD 4x4 CC just started running very rough. I started is this morning like normal and it sounded normal than while idling I first noticed the idle dropped down to about 500, then it started to feel as though it is not running on all cylinders (sounds like a giant vw bug). I checked the fuel filter and it is clean and fuel seems to flow into it well. Does this sound like an injector problem or something else? I did just recently (about 2 weeks prior) change the cps. Please help if you have any ideas.
If you've never touched the Under Valve Cover harnesses, it's probably time to fix them. First place to look is the wire harness that comes out of the driver's side wheel well and rubs on the face of the driver's side valve cover. It can start to ground out there. It might be an injector, but that won't be as severe of a miss as the UVC harness.
Thanks for the answers...so far.....1 have checked the oil again, still shows full, it was changed about 2000 miles ago. I looked at the uvc harness and it seems intact, i also tried moving it around with the truck running (sort of running) and there was no change. If it helps, the "service engine soon" light is staying illuminated, but my code reader is not showing any trouble codes. I also am noticing a small amount of white smoke out of the exhaust. Also, when I first start the truck it runs and sounds right for about 30 sec, then it coughs and sputters, belches white smoke, then continues to run rough.....
Was the old CPS still working and if so, did you save it. It might be worth a shot of putting it back in and see if that changes anything. They are known to go bad...new or not...
I had a similar problem with the truck starting and then idling kind of low.......like around the 500rpm range that you said. It seemed like it wanted to stall out and sometimes it did. It really knocked hard and shook the truck too when it was getting ready to stall. I read that the fuel needs suppliments to keep it's integrity.......I got the diesel kleen product and have used it ever since. I have not had much trouble at all with this type of event since using it. I just thought I would put in my two cents in that it might help..... and I hardly know what I am talking about...
Thanks again for the input, I think I have ruled out everything but the UVC...so...does anybody know where I can get one besides the local stealership??
Make sure you diconnect the harness at the valve cover to ohm it those lines carry 115 volts and will arc to ground if you just puncture them to do the test.
Hello again, well... went to a local truck shop and they used their computer and diag as having a #8 injector problem, which they said was most likely the uvc harness and uvc gasket. I replaced both (that was fun...) and the truck is still doing the same thing. Is the uvc connector a different part that I have not changed yet, and if so where is it? Or is this truly an injector problem, if it is can I check the injector before I but more parts??
You need to have a break-out-box test done to be sure which injector is bad. I had the computer tell me #8, and I changed it out, before the BOB test indicated #6 which turned out to be the dead one. The dealer or a diesel shop will charge about $150 for this service. It allows you to turn off each injector one by one to see which one affects the engine RPM and Mass Fuel Demanded the least.