6.0 no start confusing condition
 

Hey I know this is more than common. I am having a no start condition. When I unplug the ICP it starts and runs just fine. So no FICM issue. I already replaced the ICP and still no start.

HPOP? I dont have a way to check the actual pressure at the ICP. (scan tool is 30mi away.) I was thinking its not the HPOP because it runs so well and no dead cylinders. So I have enough pressure to fire the injectors.

I am kinda :argh: here.

I dont have a ton of expertise with the 6.0 so I figured I would ask the guys that know more than I do. Thanks for any help guys.

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update. Just pressured up the oiling system from the ICP hole and could hear no leaks et injectors.

What year truck??? Where is the ICP in the valve cover or in the back by the turbo? If you unplug the ICP and it fires, there is something wrong there. Unplugging it makes the PCM send a default signal of 2000psi, so the HPOP runs at 2000psi, and runs fine. There is either a short in the wiring or the ICP sensor is bad. Where did you get the sensor? From Ford? They are known to be bad out of the box on occasion and I've heard of issues with non Ford parts.

Also for your air test, did you get the IPR valve closed? It needs to be hooked to a 12V source and closed.

Sorry for the lack of info. its a 2003 f-550 with a 2005 6.0 reman. its on the valve cover. The IPR closed with the key on. With the key off I could hear air returning to the crankcase.

So I should be looking into an open in the wires to the ICP? I have not unwrapped the harness to it yet. I was thinking sensor. I got the ICP from NAPA.

Thanks man.

You can ONLY close the IPR fully with a 12V source and a new pig tail wired to it. The scanners can't even close it all the way, they only go to 85%. You need an outside 12V source.

Very possible it is just the sensor though if you're not really hearing any leaks.

ok. I did not know that. But it did not leak back with the key on. Is that a bad sigh?

I'm kind of surprised by this, I wouldn't think there is something wrong, maybe just hard to hear it leaking by like that!? I'd think if all it took was to turn the key forward most guys wouldn't go through the trouble of hardwiring a 12V source to close it...

Maby I just cant hear it. Anywho. I put the new sensor in. Still no start. Pulled harness off. It started and ran and I now it cranks like it wants to start. But still no start. I am thinking I am just below 500 psi.

Very possible. Might be a small leak, or the sensor itself is bad (or is this a 2nd new sensor?).

It'd be nice to hook it up to a scanner and see what the ICP values are...

this is the new sensor.

The ICP pid is: KOEO 56psi
Engine start it was around: 750 psi (Its actually started after its been sitting for an hour)
Engine at 2000 RPM: 1325 psi
engine ideling: 650psi

Are those actual values or desired values though? Desired is what the PCM is commanding and actual is what the pump is actually putting out.

At WOT going down the road it should go to 4000 or so. It needs 525psi to fire.