I was at work today driving between some of my job sites. I was creeping along at off-idle speed, and suddenly the truck registered a slight miss. After about 20 seconds, another cylinder seemed to drop. The truck started chugging heavily, then died. I started it again--roughly--and it quickly died. I thought I had run out of fuel--I was very low, but my subdivision has a lot of topography, so with all the hills, fuel level is anyone's guess. I hit the drain lever, and fuel sprayed out--obviously not out. Just to be sure, i had one of my subs put a few gallons of diesel in my tank. My next thought was fuel filter. I didn't think CPS was likely since it chugs along, rather than dying instantly. Besides, I've been running B20, and I know the solvent effect of bio will clog up the filter with old fuel tank junk. I replaced the filter, but to no avail. Next thoughts are: CPS (I assume it's possible), UVC harness, and/or HPOP (or rather, low pressure pump not feeding HPOP). I had it towed to my friend's shop and he's going to look at it tomorrow.

I know this has been hashed out before, but I believe the more specific stories are related on this board, the better it will serve the members when THEY get in a bind and are looking for ideas. That said, 1) Does anyone else have any ideas, or have you experienced this before? 2) When I do know more, I will post answers

 

It really could be alot of things, But as it sits now it will crank, idle rough (for how long?), and then die.. correct.

 

Idle rough for 5-7 seconds, max. It cranks quickly--I don't have to turn it long before it fires. But it idles very rough and dies in 5-7

 

Just a start ... my truck did very similar behavior ... it was the fuel pump. This seems to be my answer to all post like this because it is the only thing that ever happened to my truck .. knock knock (wood) ... of course i wouldn't be here now if i wasn't looking for answers for wome weird symptoms now.

 

Start with the HPOP and make sure the oil level is full (Add a little if you need) then crank engine and as soon as it dies check HPOP level again. Let us know for the next step.

 

I'm suspecting HPOP reservoir level. I think if it were the fuel pump, my filter bowl wouldn't be full

 

it could be and that is a test down the line. A weak pump could fill the bowl and be able to crank but not supply enuff volume to keep her running.

 

That is exactly what mine was doing .... It was a gradual thing ... took about a two to three days before the truck would not start .... it would fill the bowl right before starting idle fine ...take off down road to find out that when i really press hard on the pedal it would just choke and sputter .... i tried replacing ipr rings from reading suggestions in this forum etc. etc. ... got to the point it would start but be really rough idle and then die .... then would not start ..... rapped a hammer over the fuel pump with key turned on and it started pumping ... ran fine. Replaced fuel pump (near $300) worked fine ever since.

 

Update--CPS checked out and HPOP reservoir was full. We're about to pull the valve covers and check the UVC harnesses. I'll update again

 

Hey all, looking for more advice.

From whaqt I understand, the REASON the UVC harness goes bad is that glow plugs start to go bad and overheat the harness, melting protions of it and possibly the valve cover gasket.

If I indeed have a busted UVCH, should I go ahead and replace all the glow plugs? Are these expensive?

 

https://www.ford-trucks.com/forums/2...or-wiring.html

Most of the time its just a rubbed wire or loose connector that causes burns in the wires.

Ohm the GP's out if they are not between 0.1 and 2.0 ohms swapem

 

Ohming at the pin, or somehow at the plug itself?

 

UPDATE

First of all, those 9 pin connectors are a two-man job...

I ohmed everything, and everything checked out. Also, when I pull the drivers side pin, the truck dies. When I pull the passenger side, it drops significantly in RPMs, but keeps running--as if it only lost power from two more cylinders than normal

Pulled the valve covers, and all the wire are intact, as well as the gasket connectors.

Any ideas????

 

Sounds like an injector problem on the pass side. I f you have a way to do a CCT (Cylinder Contribution Test) it would narrow it down to the cylinders causing the problems.

 

any ideas on how to do that? I'm at my friend's shop, so we have lots of tools handy