Seems like the forums are full of these but here is another. '06 250 with 6.0 that has about 145k and will turn over but will not crank. I noticed a few hiccups over the past week or so but didnt think much about them until the truck would not start. When idling it would occasionally surge, quickly jumping up 50-100 RPM and dropping right back down to a normal idle. The surge would not last more than 1/2 a second or so. The day before the no start happened I was leaving a parking lot and it shut off when I let it go back to idle. It started right back up and did fine for the rest of the day. I have also noticed a couple of time over the past month or so I would have to crank the engine a bit longer than normal before it would fire. Just over a week ago I did an EGR delete and oil cooler replacement, with the exception of the few hiccups above it ran fine for close to 1000 miles - I did the work Saturday and had to drive it on a trip for work so I racked up the miles pretty quickly. A few days before I did the delete and cooler I tuned with an SCT and put the performance tune on it. Most of my trip were highway miles - 65-70MPH - and I was only getting about 13 MPG, that seemed a little low but since I had recently put the tune on it I was not sure if it would be normal.
Anyway, on to the troubleshooting. I checked the inertia switch in the passenger kick panel. I pulled the top fuel filter cap off and KOEO fuel started dumping out of it. I unplugged the ICP and no love. I read somewhere about unplugging the EBP and cooling fans - unplugged them and nothing. Using a ScanGuage II I had ~11v at the power and logic side of the FICM and ~47.5v on the output of the FICM. I ordered an AutoEnginuity kit the other day and it came in tonight. I did a buzz test, all 8 buzzed and then I heard each one clicking individually - one sounded a bit different than the others but they all buzzed and clicked. Cranking the engine I had ~380 psi on the high pressure oil side. I commanded the IPR to 0% ~380 psi, commanded the IPR to 100% ~380 psi. I have not had a chance to put air pressure into the system yet but I should be able to in the next day or so and listen for a difference in air as I cycle the IPR.
Logic tells me I either have a bad IPR that is not responding to commands and is stuck at/near full bypass or I have a leak before the IPR - since it goes straight into the HPOP is that even possible? If it was something like a HPO leak it seems like the pressures would at least change a little when I changed commands on the IPR right? When I would stop turning the engine over the pressure would not immediately drop back to 0 (actually the ICP was reading about 4.5 psi). It would take it several seconds for the pressure to drop back down. If it was a high pressure leak that was bad enough for the engine to not start it would immediately drop to 0 after I stopped cranking the engine wouldnt it?
Sorry for the long post but I am looking for opinions and I want to make sure I give as much detail as I can about the truck and what I have done so far...
BTW - from the 15 minutes or so I messed with the AE software I really like it. It would give me readings and options that a Snap On Solus would not give and certainly more than my beloved ScanGauge II would give me.
It was a challenge to get it on this trailer!
, on Flickr