96 F350 shut off and wont restart

[GilroyRacing]

I know its been a little while since ive been on here, but I need a little help fellas....

I was heading out the other morning.... I fired the truck up so it would warm up.. It was running for a few minutes, started ideling rough then shut off.

I figured it was the CPS so I went to the ford dealer bought another one, replaced it yesterday morning and it still wont fire up.

It cranks and sounds like it wants to fire up but just wont.

The GPR is humming like it always has (GPR109) so im sure all the glow plugs are fine, and I had it plugged up so i dont think any of that is a issue. I even checked the GPR it is showing the same volts as the batts

What else can i try or look at to get this thing running.

I also replaced the ICP sensor as well.

Here are the codes that came up... the only code im getting now is P0344..

P0344, P0472,P1280....i cleared the codes put 2 different new CPS in it and its still reading P0344....



thanks for any and all help,
Justin

[slammed83mazda]

I will be watching this, I'm going through the same exact thing on mine.

[glovemeister]

Any chance your idm has water in it? Otherwise do a buzztest and see how it sounds. The injectors may just not be getting power.

[GilroyRacing]

I haven't removed the IDM to check that yet...

I did do a buzz test and a KOEO test and it passed both.

[BigFuel]

When the screen shot was taken what were you doing with the truck? Sitting off? Idling? driving? Rev'ing? If rev'ing what rpm?

[GilroyRacing]

I was cranking it over. It will not fire up

[BigFuel]

There is a blockage or malfunctioning sensor (or wiring) in the high pressure oil galley. Cranking RPMs should not create a 4.12v ICP reading. At the same time as the ICP reading your IPR is near wide open trying to dump the oil pressure out of the heads at 43% (of a 50 % max). Cranking ICP readings should be in the 1-1.5v area (500-580psi in the heads).

My first impressions are that you have a short from the Brown/white wire (PCM 5v reference) to the Dark Blue/Light Green (ICP signal back to the PCM) wire on the ICP. If there is a short in the wiring the PCM is seeing a false rail pressure and is dumping the REAL pressure out of the heads causing the no start.

Pull off the ICP connector and using a meter (NOT A TEST LIGHT) test the two pins that those wires terminate at on the ICP connector (yes the key needs to be set to run). Is there voltage at both pins while it is not connected?

[GilroyRacing]

Ok, thanks. I will check that tonight when I get home from work.

[GilroyRacing]

It was dark when I got home, so I didn't get to check a lot. Tomorrow I'm going to try and get it down to my uncles shop he's right down the street.

I did spray some WD40 in it, it did not even try to start up at all.

I also checked the ICP connector. With the key on I tested all three pins... Only 1 had 5v the other two didn't have any reading at all.

[GilroyRacing]

I got the truck pulled over to the shop tonight.

I tried getting the fuel pressure gauge hooked up but for whatever reason the MAC tools kit he had wouldnt screw onto the shrader valve right so I couldnt get a reading on the FP....

I started looking the motor over to see if any thing looked out of place. I noticed on the IPR the nut and the spacer had backed off and was sitting down in the valley.

I went ahead and pulled the sensor off, you could kinda wiggle the conector in the housing if that makes any since. I ohm'd it out, with the meter i was seeing right at 10.4-10.5.

My buddy Danny (cant remmeber his SN on here) let me borrow his IPR, i'm going to put it in tomorrow and and see if that makes a difference...

In the mean time, keep thinking of possible things that could cause a no start problem.