Well guys I am pulling my hair out. Just got the motor back in and hooked up after doing studs, gaskets, oil cooler, HPOP,IPR,clutch and fluid damper. The truck wouldn't start, good fuel pressure and low pressure oil.So I recheck for HPOP leaks, none found. Next hook up PDS find ICP pressure all over the board (250-2800 psi). Replace the pita sensor.So I figure I got her licked.....No start.. Went through the harness that I checked when the motor was out,its all good. Need to check the IPR to find out if I got a bad one out of the box. Anyone ever got a bad new sensor? Is there anything I am over looking?

 

This is going to sound silly but how long are you cranking it for?

I have heard that these motors sometimes are quite difficult to restart after the rails have been drained of oil, sometimes as long as 2 minutes of steady cranking to get them to fire, and if you stop halfway the oil drains oil and you have reprime it again.

Maybe crank it for a solid minute or two and see what happens.

 

Jason I cranked the @#%* out of it.

 

Damn.... I was hoping I had an easy answer for you. I would discount the possibility that you got a bad ICP out of the box, but is the new sensor reading exactly the same as the old one? If so you may not have had an ICP issue to start with. The other possibility is the IPR may be bad as well.

I'm wondering if you don't have a leak on the high pressure side. If you have a line that you can connect to the test port for the high pressure oil system, crank it for a bit, then open the line and crank it again, see if the oil is all frothy and aerated, that would point to an oil issue. I know you checked it... I just covering the possibilities

Other possibilites: Are you getting fuel to the cylinders? Any kind of smoke at all out of the tail pipe?

If not check the FICM, IPR and ICP connections; I had mine get no start on me once because the connectors on the FICM weren't properly seated.

If yes and it's white ugly smoke check the glow plugs, I know these can sometimes no start if the glowplug controller is failed. Although for the amount you cranked it I would have expected it to fire with or with out glowplugs.

Confirm the fueling first, it's probably easier than the oil. There are basically 3 things the engine needs to run: fuel, oil, and the electronic control system, one of these is obviously not there for you, we've got to figure out which one.

Is it throwing any codes when you try to start it?

 

I am not getting fuel out of the injectors so no smoke.No codes I am going to check the ohms across the IPR next. The wiring was my thought until I double checked everything. The IPR is new so I figured it was good,now after checking everything else I am back to questioning it. The oil is fresh and clean.I cranked it enough that any air in the oil in the rails should be purged. This is driving me nuts.

 

Just some questions cause if you are pulling your hair out, you might be beyond rationale thought.
1. Fuel at HFCM?
2. Fuel at secondary filter?
3. Prime three times with key on, fill the bowl for the secondary fast?
4. Can you hear the tank pump, does it sound normal?
How many miles, is your fuel pump (in tank) going out on you?

 

I get 55psi on the rr gauge (can get up to 70)so I am getting fuel through the heads. The injectors all respond on PDS so that takes them out of the equation.

 

My sympathies, I would be at my wits end.

Seems like HPOP check like above by X is your problem but I would try what X says above and re seat all those big bundle connections to FICM, IPR, ICP and anything else you unbuttoned and buttoned back up...

Try to resist the urge to put a wrench through the windshield :-)

 

Here's the list of checks I got from a manual (it sounds like you have the tools to check these):

Check engine oil pressure. (You said it's OK)
Perform KOEO on demand self test.
Perform KOEO injector electrical self test.
Check fuel quality.
Check FICM voltages (low or no voltage condition points to wiring)
Check glow plug control module circuit (confirm resisitance to ground is above 10000 ohms before attaching to starter relay)
Check glow plug control module, glow plugs, and connectors (this test looks at the entire glow plug circuit checking for shorts, opens, and proper voltages)
Check for ICP sensor bias
Check EGR for proper positioning.

Some of these tests are pretty involved, let me know if you need better descriptions. You may try disconnecting the ICP entirely to test, apparently if a ICP high or low condition is present the PCM is supposed to estimate ICP and run in open loop.

 

did you just replace the oil cooler or do a complete removal and relocate?

 

One other thing I just noticed:

If ICP is less than 725 psi you will get a no start condition.

 

X I tried the ICP disconnect and she still didn't fire. I am not getting the injectors to fire, so no fuel to burn.I just checked the icp connecter and got 115 ohms resistance infinite on both others. The Ipr shows 5.4 ohms resistance.Do these sound correct?KOEOs both check out. What is icp bias? Denman its stock. Thanks guys I need all the direction I can get on this one.I was thinking about the IPR reading back to the confuser what is it used for? Does it tell the computer the percent the valve is open and send that to the FICM to fire the injectors?

 

when you rehooked the rr fuel system, is there any chance you switched the fuel lines around? (never seen one, mabey you switched the supply/ return lines so it actually isn't getting fuel to the heads?)

 

They only fit one way,I checked this out when I first tried to fire it up. Man I need a drink! Thanks for keeping me on my toes though.

 

The IPR checks out, (3.0 - 15.0 ohms). I'll step through the rest of the IPR tests:

Check the IPR system voltage.
Key on, engine off
Measure between pin 1 and ground.
Voltage should be greater than 10.5V, if not repair the circuit

Check the IPR circuit for a short to power.
Key off
Disconnect the PCM engine harness connector
Key on
Measure the voltage between IPR solenoid control circuit pin 2, harness side and ground.
If any voltage is present repair circuit.

Check the IPR control circuit for a short to ground.
Key off
Measure the resistance between the IPR solenoid control circuit pin 2 harness side and ground.
If the resistance is less than 10000 ohms repair the circuit.

Check the IPR control circuit for an open.
Measure the resistance between the PCM engine harness and connector pin 2 harness side and the IPR solenoid control circuit pin 2 harness side.
If the resistance is less than 5 ohms the PCM is faulty and needs to be replaced.

I know you don't want to hear that last conclusion but based on your descriptions I'm starting to lean in that direction.

The ICP test Is a 12 step series of checks confirming voltages and resistances similar to the IPR checks.

I think we are starting to get to the root cause here, and I think it may well be the PCM. But you're going to have to get through all the checks first.