yes, one of the first things i did, and should of mentioned here is that i returned the truck to stock and removed the tuner. it was on stock tune when it died on the way home. i have a fuel pressure gauge at the fuel bowl and its showing 50-60 psi while cranking. when the truck does run, it's got ooodles of power, and at wide open throttle it only draws fuel pressure down about 10 psi. however, when i go get the truck i'l bring it home, empty the fuel bowl and watch it refill to see if the gauge is correct. i am not above any suggestions whatsover. and it will just be another thing off the checklist.

 

Sounds electrical to me. Check all wires, and buy the ford CPS. Its the same price as the auto parts store part. You said #30 fuse was burned, Check it again and don't plug the fuel heater back in.

Chet

 

Kinda the same symptoms when my IPR went out. If you unplug it and check the ohms reading across the two pins. You should have 1-3 ohms(can't remember the exact number). When mine would do this I had 10-11 ohms. Replaced it and hasn't died since. This is just the electrical part of the IPR so if you have another one laying around you can just replace that and not pull the whole thing.

 

I had the same symptons on an 86 6.9. Check EVERY connection in the wiring harnesses. That was where I had a problem. When truck got warm or hot 1 of the pins in the connector itself was not conecting or completeing the circut and truck would shut down . Then when it cooled down it would start & run fine. I ened up by-passing connector with a jumper wire.

Ps look for a burn or black mark inside of connectors

 

I'll ohm out my ipr tomorrow if i can get it to shut down in the drive way, before and after. I also have new valve cover harnesses, i recently did the glow plugs on the drivers side, think maybe i should splice in a new valve cover harness tomorrow? And will it be very evident of a burnt pin? A nice brownish mark underneath a pin or something?

 

Brown or black, or look for marks where it could be arcing.
The 6.9 was a nightmare. Sometimes it would run fine for weeks and then quit. Other times 2-4 times a day.

 

Do you think the uvch's could cause a no start situation? Wouldnt it just shut one bank down instead of both of them? Im going to go digging in it today.

 

So i just let the truck sit and run for a half an hour out in my driveway. While it was running i check everything all over. Wiggled every wire i could. Fuel pressure and everything was good. After it was up to operating temperature, i shut it off, running fine mind you, and immediatley tried to restart it, it would not. I checked everything, i checked all the fuses, i checked the fuel inthe fuel bowl, which was filled to its proper level, i checked the fluid in the hpop resevoir which was a half inch down as needed. I then unplugged the valve cover harnesses, checked the pins, there was no apparent sign of arcing. I double checked them, unplugged one side and tried it, to no avail, then tried the same thing with the other side, to no avail. I unplugged, the icp, and that didnt help, i also replaced it a few months ago anyway. i unplugged the temperature sensor thinking that would help, and it didnt obviously. I wiggled every wire i could find. So i waited another ten minutes and the thing fired right up...no hiccups, like air in the hpop lines, no slight misfire..no nothing. Just a good running engine. so the two things im left with is either the ipr, or the idm. There should still be white plumes of smoke coming out the exhaust just as if my glow plugs werent working and it was winter out correct because of the excess fuel and no firing condition? Im thinking the injectors might not be sending fuel. The ipr, and the idm could cause this correct? When an idm craps the bed does it have symptoms at first or does it just go? Same for an ipr? Just picking your wise brains a little bit. Im leaning towards an ipr and do you think my new t 500 installation may have triggered its early death?

 

My bet is the IPR. My truck did the exact same thing. They are available from Clay at Riffraff.
http://www.riffraffdiesel.com/mm5/me..._Code=F731-OEM

 

Subscribing to thread. I have a 2001 doing the same thing, so far cps is not the culprit, has been changed witrh Ford one, wiring has been checked, also removed Superchip. It has ran fine 1 1/2 weeks since but am thinking of checking ipr after next fit. The only code thrown has been transmission (VSS), replaced, wasn't it, the OD light was blinking, Probably caused by the engine trouble. Mine may run 3-4 months between FITS, then perfect for no certain amount of times. Good luck....

 

The next time the truck won't start, use your scanner to check the injection oil pressure reading and IPR duty cycle while the engine is cranking. If the IPR is at fault, the oil pressure will read low (a few hundred psi max) and the duty cycle will steadily rise.

If the pressure is good (> 500 psi) it might be an intermittent IDM problem.

Also check your voltage while cranking, it has to be > 10.5V for the engine to start.

Chris

 

any chance that when it gives you fits... it coincides with less than 1/4 of a tank of fuel?

possibly crud in tank... varnishy fuel..
or sucking air?

just dealt with similar symptoms and immediately checked condition of fuel while it was acting up.

stuff is indistinguishable from wvo.
pictures in the "If your truck has been sitting" thread.

xtof

 

so i undid all the wiring harnesses i could find and redid them all. i paid special attention to the one on top of the left hand valve cover that connects to the valve cover harnesses because i undid it when i did the glow plugs a few weeks ago. i made it sure it was securely fastened, rechecked all the fluids, fuel bowl and such, fired it up. and its been fine every since. i went on a fifty mile drive with it and left it running while i filled it up. i shut it off multiple times and its been fine. i'm going to risk it and drive it to work tomorrow. i've ordered a new ipr anyway to have as a spare, i dont believe i'm lucky enough to have a loose connection be the problem. i'm officially eliminating the cps as a problem because it's absolutely fine now. the next time it gives me fits i'll check injection pressure and icp pressure. and i'll just save up for a spare idm as well i guess..stuff to add to a nice emergency roadside kit i guess.

 

actually, there was exactly a quarter tank in it when this problem arrived. but why after an hour would it be fine and start right back up? and no extended cranking either, one second you could hit the key and get nothing for a minute of cranking. walk away for a few minutes to get a drink, come back and she fires almost as soon as you hit the key. fuel pressure was fine all along as well, atleast at the fuel bowl. i emptied it and watched it fill back up to confirm. and the fuel filter seemed very clean. batteries are less then a year old and i load tested them a few months ago. maybe it was just a loose connection, doubtful, tomorrow will be its trial day.

 

yah mine did the exact same thing...
im thinking after she sat for a few... the crud fell back off the filter and allowed the good fuel to get thru and hence the smooth running afterward. when i drained my bowl... what came out was nasty... varnish smelling... but it filled back up clean and she is fine now.

probably going to drop tank this week and clean out, do the hutch and harpoon mods and see if that cures my problem.

xtof