i need some help from a real powerstroke head. i am about to give up and sell my truck cheap because i cannot, for the life of me, get her running again. I now lay out in sequence the unfortunate chain of events that have left my truck dead. ftr it is a 1997 f250 7.3 DI 4wd auto. no known mods, 340k.
bought the truck last year and used the heck out of it everyday. maintained 3000 mile oil changes. ran good for several months, then....driving on freeway i noticed the cel come on and an immediate loss of power. She still ran just with about half the power. I could put in neutral (rolling) and shut off, turn back on and drop back in drive and she was normal again. this would last a few miles or 50 then do it again. very sporadic. Unfortunately i just lived with the problem for about a month. Driving only a few miles from home one day she died at a stop. restarted but alot of cranking, drove abouta mile, died and would not restart.
So we towed it home and hit the forums. I have already put 2 different cam position sensors in, a new lift pump glow plugs, tested relay, checked fuse 22 or whichever is linked to fuel heater. I had noluck so i took it to a mechanic. He found that the wires to the ipr were touching so he put a new pigtail on and the truck started and ran. He then monitored the hpop running pressure and found that when the truck reached normal op temp, the hpop pressure was increasing unchecked toa ceiling of 3000 psi and held at 3k. the truck would start chugging and die. Wait ten minutes and restarted. tried to drive it home to keep working on it and got about 15 miles when, climbing a hill, she lost power, died and refuses to restart.
so far i have dropped about 600$ into her and still no run. Any help would win you god status in my eyes. thanks for bearing with me, i dont mean to be too wordy, but want to cover all the bases.

 

Phil it's Blake. Glad you found the site and good post, so i have a few more questions. Have you checked the fuel pressure? And do you have access to a scanner to maybe read codes an more system vitals. I know you said the mechanic had a scanner but dont know if you know some one who can do it for free if the mechanic charges you.

 

Lol, hey blake! you are everywhere. the biggest problem is the truck is at home 25 miles from town. there are people to scan it there but getting it there is a big production. i might haveone guy closer who can check it out on thursday night....he charges too tho. how much for a scanner that is compatable? that might be my best bet.

 

Btw I was born In k falls

 

Yea being out of work right now has freed up a lot of time lol. And im sorry to hear you were born in k-falls lol just kidding, i went to OIT for over a year but couldnt stand living there any longer so i left last term. Yea im wondering if theres any codes stored that could help, but it would help more if the truck ran and could read the vitals lol. And theres two scanners people use, well ones a scanne the other is a guage. AutoEnginuity is a scanner that you plug in and can read what your obdII port is seeing. Then theres the scanguage, it reads vitals, performs test, reads and clears codes. Someone with more knowledge on scanners will come along.

 

Sure be nice to get the codes read. Is there any white smoke while cranking?

 

Have you tried unplugging the ICP and then cranking it? If the mechanic said your HPOP pressure was going to 3000PSI and hanging there it sure sounds to me like that is where you should start. Unplug the ICP on the front of the driver side head. Look inside the connector for oil. If there is oil in the electrical connector, the sensor is likely bad. The other possibility is that it may need IPR o-rings. Check the ICP and report back. We will get you going again, just don't give up on it.

Here is a picture in case you need help finding the ICP.

 

Nate, is the indicated pressure (3k) a sign that the ICP is possibly bad? why? Just learning the oil system and thanks for any detailed info.

 

I just went through a nearly identical problem on my 97 7.3. Final result: $535 with a new $180 ICP Sensor. Runs like a champ. I tried everything suggested including pulling the ICP for cleaning and o-rings, new CPS, GPR, Fuel Filter, Oil and filter change before taking it to the shop. Good luck. PS you can find a new sensor on E-bay for $70 +\-.

 

ok thanks very much for the ideas guys. I will try that stuff later this morning when the moon goes down and sun comes up. All of your concern has renewed my drive to get her fixed. ill stick with it and report back soon. thanks all!!!

 

When you get it on a scanner, We need to see IPR duty cycle % & ICP pressures & volts while cranking . Make sure the oil is full & clean & the HP res is full to start out & the batteries are up to it .. ..Do a buzz test so we can see the codes in stored in the IDM if any ...

 

The way our HPO system works, the pump is a constant pressure, constant volume pump. The ICP reads the HP oil pressure in the head and sends its signal back to the PCM. The PCM decides what HPO pressure it wants to see based upon engine load, throttle pedal position, engine oil temperature, boost levels, engine speed, etc. The PCM then sends a signal to the IPR which is essentially a solenoid valve to either open and close to increase or decrease the HPO pressure. The IPR opens and closes to bleed off the pressure to maintain the desired HPO pressure.

With this being the design, if either the ICP is reading a false oil pressure, or the IPR is sticking, the HPO pressure will not be kept in check like the PCM wants it to. 3000psi is way high for just cranking the engine over. That is about what you would expect to see under heavy acceleration. The only other thing that I can think of that would cause that high a pressure would be if the injectors are not firing at all and the HPO system essentially isn't using any oil. If that is the case you would be seeing no smoke while cranking, which could still be a symptom of a bad ICP.

Unplug the ICP and try to start the truck. See what happens there and let us know.

BTW, for anyone wishing to learn more about the design and function of the HEUI fuel system on our trucks, here is a link you need to check out.
Ask a Mechanic - A deep look at the 7.3L Power Stroke

 

The ICP at 3000 is most likely not correct ..It may be only what the PCM is asking for if the IPR is not responding .. Like was posted, unplug the ICP sensor for a test as well . It will set a CEL

 

Good point Rick, it depends how the mechanic was measuring HPO pressure. It would be nice to know whether he had a mechanical gauge on the system or was just reading it from the PCM via a scanner.

 

he had a fancy 1000$ dollar scanner to read the pressure. when i picked it up from him, it would start normal and run fine cold, but as op temp waas reached it wouldincrease unchecked to a ceiling of 3000psi which would kill the engine and make it a bitch to restart unless i waited 10 minutes or so. I tried to drive it home (he didnt have time to do anything else with it) and after 15 miles it lost power and died with no hint of restarting. i will go try these suggestions right now with brand new batts. the oil is due for change with about 3k on it. ill do that just for good measure. and hey whats another 50$ right