I have a 2003 F250 Super Duty with the 7.3L and was hoping someone could help me figure out what might be causing my problem(s).

I have the following symptoms:

- Occasionally it will have a rough idle. Nothing really bad. Just feels like a miss.

- It randomly stalls when at idle and sometimes while driving. The while driving stalls seem to be when at low throttle.

- It intermittently won't start. It will crank but not fire. I have discovered that when this happens locking and unlocking the doors using the factory alarm remote seems to solve the problem. In other words, if I cycle through locking and unlocking using the keychain alarm remote it will then fire right up.

- I tried to pull codes with two different scanners. Neither one was able to communicate with the computer for some reason.

Any advice would be greatly appreciated.

Thanks.

 

Codes would be a huge help for a starting point if you can come up with them.

That said, without them, i think i would unplug your ICP sensor on the drivers side head and drive with it unplugged for a day. when you unplug it, if th econnector looks full of oil, that is a definite sign it is on its way out. You can run with it unplugged safely short term, as it will use default values for ICP. Its a free place to start at least.

 

On the scanner issue, an OBDII scanner will not pull codes on these trucks. You will need something like AE or similar. I have had similar issues (didn't try the lock/unlock thing since my power locks don't really work anymore) and I ended up replacing several sensors hunting. I still have a bit of rough idle and miss at low throttle. The best result I got was after replacing the ICP wiring harness and removing my chip. It has not stalled since, but I don't know which one of those partially fixed it.

 

Thanks for the input. I will try unplugging the ICP sensor and find a place with the correct scanner to pull codes.

I appreciate the help.

 

What CPS (cam positioning sensor) are you running?

 

I'm not sure. I just did a search because of your question an apparently there was a cam sensor recall. I will check with a dealer and try to find out if the recall was performed on my truck. I bought it about a year ago so it is possible the prior owner didn't get it done.

 

CPS would be the first thing I check, the ICP is a free check, just unplug. Also the IPR could be giving problems, the IPR itself or the electromagnet surrounding it. (ask me how I know, lol) UVCH could be intermittantly causing problems. How old is your oil? Checked level of oil lately? Remember the injectors are driven by the oil. Has the CIL come on? The harness that runs over the drivers side valve cover is know to get chaffed and cause some random shorts/stalls. More knowledgable folks will chime in I'm sure.

 

I was just reading about the black vs. grey vs. dark blue CPS versions. Sounds like the dark blue is best? If I have to replace it I will try and find one of them.

Oil is full and brand new. The CIL has not come on. I'll check the harness for chafing. Thanks for the heads up.

I just watched a video on youtube about the UVCH. I think I will go ahead and check it regardless and put the quarter in even if it's not loose now.

How would I check the IPR or the electromagnet? Is there something specific to look for or a test to perform?

Thanks again. I really appreciate you guys taking the time to give me the information.

 

As far as the IPR, I believe it can be either a oring that leaks pressure or the internal workings may have a small obstruction. Honestly, I would'nt worry to much about the electromagnet, this is a very rare failure and besides mine, I've only heard of a couple other failures. In order to test the IPR you need to be able to see what kind of pressures are in the high pressure oil rails. A gauge that reads to at least 3000psi, a hose from the gauge to the head of the motor. That connection requires a #5 oring boss fitting. When the problem flares, reading pressure while cranking is what you want to see. I forget the psi you should see during cranking, like 300psi plus. When mine failed, I didn't even see 100psi in the oil rail. There are threads on here that discuss the necessary psi, putting together the gauge, port locations, etc. Also, a good thread on here about rebuilding the IPR, pretty easy actually. Dieselorings.com sells the kit, it's cheap. Cps? Yea, I think the blue one is the desired one, think the borg warner one from orielly's is pretty good, that's what I'm running for the last two years. Wish I could link you to the threads I mentioned, just not that computer savvy. You will probably see a few threads started by me, if you search for info on the ipr, lol.

 

You can also search for a thread started by me titled "bucks and dies, about to give up", or something like that. IIRC someone either posted the info for testing the IPR electromagnet, or linked to it in that thread. Grant also posted a very helpful link to troubleshoot IPR, ICP, and other pigtail connectors. I would link to the thread but have yet to learn how.