Intermittent no start

[svonasek]

I've got an 03 f350 with a 6.0 powerstroke. I've been having some strange problems with it.

A week ago I drove it for about 3 hours. I parked it and shut it off. The next morning it would crank, but not fire.

I borrowed a scanner and it indicated that I had an open cam position sensor. I replaced the cam position sensor and it still didn't want to fire up right away. I had to do a few long cranks then all of a sudden the oil pressure gauge jumped up and it fired right up. I kept checking it every couple of hours and it continued to start each time. The next morning it fired right up. I drove it about 30 feet and it died like I had turned the key off. It would then crank and not fire.

I replaced the oil filter just to be sure. After sitting for about 10 hours it fired right up again. I continued to start it every now and then for the next 3-4 days and it would fire right up each time.

A couple of days later I drove it for about 1 1/2 hours. Everything was fine. I shut it off for about an hour. I came back out and it wouldn't start. It also wouldn't register oil pressure on the gauge. I did a series of long cranks with no luck. It wouldn't build pressure. I had it towed home. As soon as it was on the ground it fired right up.

I now have a scan tool. I've been monitoring the ficm voltage and the oil pressure. Everything looks fine while it's running. The ficm is at about 48.5 volts and the oil pressure jumps to about 700 within a half second of cranking.

I pulled the low pressure oil bypass apart and it seemed to move freely. I took the oil filter out and I get oil flowing up into the oil filter housing.

Anyone have any ideas?

[southend]

It almost sounds like icp sensor and/or pigtail. Is it oil soaked? What filters are you using? How are you reading the hpop pressure? Do you have a monitor?

Sent from my SCH-I500

[svonasek]

The oil and fuel filters were all replaced with motorcraft filters. I'm using a scanner to monitor the icp. When warm the icp spikes to somewhere around 1300 withing half second of cranking and then settles down to around 640 when idling. This morning after sitting over night the I saw 1900 while cranking and then settled to around 840 when idling.

I've been starting and stopping it for a few days now trying to get it to fail again. I'm tempted to just through an ICP at it, but I'd like to have it not start while I have the scanner on it so I can actually see what's wrong. I really don't want to just through parts at it.

[southend]

Yea, your thought process makes sense. Thats what I was thinking.

Sent from my SCH-I500

[dannyboy950]

I sugest checking actual fuel pressure with a mechanical gauge. Your low and hp oil pressures are good. Also check ficm voltages and for sync while cranking.

[nylyon]

Last year mine did this too. It turned out to be the ICP pigtail. If it happens again, go under the hood and "massage" the ICP wiring harness to see if it starts up.

[svonasek]

I tore it down a little tonight, but I don't see any oil on the connector. It did seem like the middle connector on the ficm module came out and I don't remember pressing the tab to disconnect it.

So I'm back to waiting for it to not start so I can see what the scanner has to say.

[svonasek]

I'm still concerned about the time it wouldn't start and wouldn't register any oil pressure on the dash gauge. I replaced the oil,filter, cap and the drain valve today hoping that it would be something simple.

I know I read something about a check ball in the HPOP that blows out. Will this cause an intermittent problem or once it's bad it's bad?

I took it for a drive today and everything seemed normal. Then out of no where the truck just shut off like I had turned the key off. I had been watching it on the scanner and everything seemed normal. My ICP is reading about 640 at idle after warming up. I've seen it as high as 2400, but that was just while driving around the block. The ficm voltage is staying right at 47.5-48.5. My ipr at idle sits about 22.4-22.8.

I still haven't received another code. The original one was about an open cam position sensor. I replaced that first. Is there any kind of known problem with the CPS wiring?