96 F250 Powerstroke - died and won't start

[sjk]

Driving completely warmed up (30 minutes or so) and the engine died. (As if I had shut off the ignition) Will not restart.

No codes. Engine oil pressure during crank is good. Fuses and relays all okay. I verified the UVC Harness is completely hooked up - heard this is a common problem. Replaced Cam Position Sensor - also heard that this is very common and will produce common symptoms. Fuel pumps are delivering fuel fine. Still no start.

There is no fuel going into the engine - as I crank, no fumes at all coming out exhaust. Very different from a glow plug relay failure symptom.

Any thoughts would be very appreciated... I'm almost ready to tow it in for some help. :-(

Thanks,

SJK

[sjk]

Quick update... I just checked the oil pressure at one of the high-pressure oil galleys on one of the heads and it only registered 250 psi while cranking... I expected more. How much pressure should it be creating while cranking?

[ModMech]

That would be low, IF the EEC knew you were cranking it over. It will run on that, but poorly.

I would first suspect the CMP (cam sensor), easy to change but not exactly inexpensive (although cheaper than other ideas). It's easy to get from below, mounted at about 11 o'clock relative to the waterpump pulley. One 10mm bolt and a three wire connector.

[moparboy99]

I've worked on trucks like this but alot bigger the truck I work have about 4000 psi going to the injectors to fire them they call this system the huei
injection but I'm betting the pump is bad they have a seperat pump at least the truck I work on do

[ModMech]

I'm sorry, but you don't have this right. The system is called HEUI, but that is all that's correct about your post.

If he follows your advice, he'll be out over $1000, and still not have a running truck, because the injection presure is controlled by the EEC and the EPC solenoid. During cranking, you should see it rapidly raise past 800 PSI. This "test" ASSUMES the EEC knows the engine is turning over. If the EEC does not get a signal from the Cam Sensor, it has NO CLUE you are stying to start it. Furthermore, he has NO CODES, and any failure in the HEUI pressure system (pump, EPC solenoid, etc) WILL flag a code.

[sjk]

Fixed the problem - thanks for all your help. Here's the details...

As mentioned in the initial post, the engine died and was delivering no fuel to the cylinders.
(1) I started with the Cam Position Sensor (CPS) - replaced it ($120) and still no start.
(2) I was told by a local powerstroke mechanic that they ran into a problem with the fuel heater element (just under the fuel filter) that shorted out, causing fuse #22 to burn. The injector controller is on the same circuit. I checked all the fuses in the truck and all were good. Still no start.
(3) The low pressure oil was okay - the idiot guage was coming up when cranking indicating that I was getting at least 7 psi. So I decided to test the high pressure oil system. I was only getting 250 psi.
(4) I asked the local mechanic if there's a pressure relief valve in the High Pressure system, and he said NO, the injectors act in this capacity. He said to first isolate the heads to make sure that an injector isn't bleeding off oil pressure. I tested the system disconnecting each side and still got the 250 psi reading.
(5) The high pressure oil pump rarely goes out - but there's this valve called the IPR Valve (Injector Pressure Regulator Valve). It screws into the bottom of the high pressure oil pump, facing backwards on the drivers side. My local mechanic recommended replacing that valve before pulling out the pump. To replace the valve, you must remove the fuel filter assembly.
(6) I put the new valve in ($250) and cranked it over to test the high pressure oil - it pegged my 3000 psi gauge.

Put it all back together and she fired right up.

Thanks again for your input. Hope this detail helps someone in the future!

SJK