99 7.3L engine misfiring? Won't warm up.. no codes thrown

[uc07]

As of 2 days ago my 99 7.3 Powerstroke has been running rough. It was running fine and I turned it off, when I started it back up within 20 minutes or so it was skipping at idle and throughout acceleration. If I put my foot in it she has tons of power but is running rough. I'm thinking injector problem? I have a Hypertech ECON programmer and there are no DTC's reported. I also noticed the engine temperature won't come off of cold very far at all, even in 60 degree weather like today. Although, the warmer the engine temp gauge rises, it seems to smooth out. Any ideas? Thanks.

[BPC Bugman]

Being a 99 I'm guessing it has maybe at least 100k on it. Have you changed the oil in the high pressure oil pump that actuates the injectors. I did this on my 2000 7.3 70k and it made a huge difference. There is a guy on youtube that explaines exactly how to do it in video, search powerstrokehelp.com or go to youtube, lots of info!

[Rudolph]

Doesn't just changing your engine oil like normal automatically change the oil in the oil pump resovoir?

[robammerman]

I would look at your oil temp. sensor. The PCM monitors the oil temp (which is what your gauge runs off of) and adjusts the timing accordingly. If it's getting a wrong reading, your timing will be off. Just an idea.

[uc07]

It looks like I have a bad PCM, I'm hoping that's the problem.

[drsmith3]

i have a very similar problem. truck sits a lot. i drive my company truck. but they called them all back so now im driving my 97 dps. this has happened to me before. ususally i just change the oil and its ok. but this time it has not smoothed back out.

[Rudolph]

How do change the oil in the hpop? I've never heard of that before.

[TommyBoy#1]

me neither ???? i thought when engine oil was changed everything was changed need more info

[uc07]

powerstrokehelp.com has a video describing how to change the hpop and they recommend it because that oil up there doesn't circulate like the rest of the oil, it sits up there under pressure. When I changed mine, I drained the oil and before I refilled the system with fresh oil I used an oil pump to pump in a gallon into the screw on top of the hpop reservoir which forced the old oil out and the fresh oil in place of it. then I poured the remaining oil into the oil fill as you would normally do.
I'm waiting to receive my new PCM and have hopes that it being bad is the cause of my engine problems.

[uc07]

Oh boy... the new PCM arrived, I put it in and it didn't make any difference, the OBDII port still won't communicate with and diagnostic equipment or the programmer. The fuse for the OBD port is not blown. It looks like I'll be tracing wires in the dash now trying to find the problem. This sucks....