Well i'd post this in the correct forum but it doesnt really matter, i'd like to see what my "fte" brothers have to say about this--

Got the engine installed in the 95 finally after having virtually no time to work on it. Got it started the other day, and it ran very rough, long after the time where i thought air would be out of the system. Hooked up AE and found IPR duty cycle to be 50.00% when cranking, and pressure "slowly" built, once the engine started it held 1300-1800psi of ICP (AT IDLE). You can imagine how it sounds. Very clackly and clattery. Push the pedal and nothing happens, a few seconds it will run to 1500 rpm relatively quiet, let off and will return to idle but keep the ICP and sound horrible again. Duty cycle at idle is 20-40% it fluctuates very badly. I've pulled the IPR and cleaned it, reinstalled and same thing. Took a "sticking" IPR from pete's trash pile and cleaned it, and still same thing. Called Jody this morning to ask what he thinks. Said to pull the ICP connector, will default to 750psi. No change in the performance. Then bought a new IPR from IH, installed it still same thing. Swapped out the ICP sensors from my truck, and still SAME freakin thing. It has fuel and fuel pressure, it has significant oil in the HPO reservoir. Anyone got an idea?

 

Is it smoking? Have good rings and or compression? Did you do a buzz test?

 

AIR.

All the air is not going to work out until it is under load, and driven.

 

Yes, smokes blue some, simply because it's cold. I had the right head off, , but never checked compression. Ran great before we pulled it to fix several leaks and bad oil pan. Not sure if it's a loose UVC connector (there are four on an OBS powerstroke, but cyl 5&7 are both low on the buzz test and throw a code. Possibly the connector under there is loose? It has a new gasket.

 

Well, we'd try driving it around, but we can't even move it. It's so frail and weak that i feel sorry for the truck idling with that much ICP so i dont run it if i have to. Sometimes the ICP would drop down to 1100 but it never got close to where it should be. I don't think air could cause that high of an ICP.

 

You could try running it without the valve cover and mess with the harness? How cold is it where your at? Blue is oil ya?

 

It was mid-low 50's today. im not sure about the valve cover off idea. But, i can try ohming out the GP's on that connector and see what they say. What i really need is four new retaning clips on the plugs, as they have snapped off in the 13 years of use and now they aren't secure, but still stay in the plugs in the meantime.

 

Ohming would probably tell you if there still connected right? Did you change the head gasket when you pulled the head?

 

Of course i did.

 

Something I have learned about troubleshooting is I tend to overlook simple things by looking too deep into a problem. If the IPR is not the problem. . . and the ICP is not the problem. . . then something else is commanding the high dutycycle. Do you have another computer to throw in there?
Tim

 

High duty cycle usually indicates a leak in the HP system, O rings IPR or the Injectors.....

 

Hmm, sorry to kinda go off track for a sec. but this thread interested me about a potential problem I may have. I have a feeling my ICP sensor is going bad since twice I had a hard time starting my truck.. and pulled codes leading to the ICP sensor. Just the other morning, I started the truck and let it warm up for about 5 minutes in upper 40 degree weather. When I pulled out of my driveway and headed up the street, I had literally no power. The truck was barely going 10-15 mph... barely got out of 1st.. (slow power increase). After about a half mile, I came to a stop sign. I pulled out from the stop sign and everything was good again.. turbo kicked in, etc.

Is this possibly a sign of a failing ICP sensor or was the truck just not warmed up enough? I only drive it about 2 miles to work each morning so it never really warms up fully.

Just wondering since if this is ICP sensor problem.. just so I can go ahead and buy a new sensor.

 

Unplug the sensor, assuming you know where it is. Then do a test drive and see if anything changes. The PCM defaults to a predetermined pressure at a certain engine load instead of getting a live reading from the sensor.

 

Yeah, I know where it is. I'll keep driving it until it acts up again.. and go from there.

 

I am thinking more of a stuck EBP valve than an IPR.