Engine/Transmission (1994 - 1998) Engine dies on freeway, under load (not new, right?)

[BFurton]

Just picked up the truck from the shop. They could not find anything wrong with the truck. I asked the to do additional tests on the fuel system, vacuum test- lift pump to tank, passed in spec. < 4 in. Hg. Fuel Pressure @ spec to the filter/injection pump. 27PSI. Fuel Return line, no restrictions.....
When I got home I decided to check the measurement on the Fuel Shut Down Solenoid. It measured 2.75", from the top of the clevis pin to the bottom of the solenoid mounting plate. OEM spec-Dimension should he 66.9 mm (2.64 inches). So I have adjusted it to that spec now.

My question now is this, What influence/significance is this rod adjustment in relation to the problem that was originally described? If this rod is adjusted to long, will it shut the fuel off at some point (or starve the IP, or otherwise act like its running out of fuel)?

 

[GAmes]

If the lever isn't pulled all the way up the truck will lack for power when you mash the pedal. Not too noticeable empty, real noticeable when trying to pull a trailer up a hill. So if the rod is too long the lever isn't pulled full up.

 

[BFurton]

Thanks GAmes!

 

[BFurton]

UPDATE: After I made the correct adjustment, I decided that it was quite easy to pull out the newly installed OFV and measure it's opening pressure. It measured ~14-16PSI after several attempts/measurements. So, I replaced that one with the one that I had previously purchased from TorkTeknology (adjustable). I measured this one too. It measured 25PSI after several attempts/measurements. So, I adjusted that one to 27PSI and installed it.

It's now been >4,200 miles and not a single lick of problem.........until today. It quit again just like before. And, just like before, I got out checked the fuel shut off solenoid (it was up). Tried to restart it a couple times - nothing. Then got out and like before, primed it again. Fired right up, ran rough for a couple seconds (probably because of trying to restart a couple times) then I was on the road again.............???? Go figure.

Now then, I also replaced my fuel cap (locking from Geno's). I have noticed that now when I fuel, unlocking the cap I hear it hissing (pressure I think, not vacuum).

This is baffling me...

 

[MLee]

Maybe try leaving the cap loose to equalize the tank pressure. The vent on top of the tank might be sealed/closed. Check that out.

 

[GAmes]

My tank has had a hissing noise when the cap is removed since day one. The pressure inside the tank and how it is regulated are covered in the factory service manual.

 

[Missouri Mule]

If it dies out again take your fuel cap off and see if it starts.

Several members had trouble with engines dying. They took their trucks to Cummins where the tech found the engine speed sensor/crank speed sensor was acting up
Causing stalling but eventually they were sble to restart the engine. Your problem?.

How much fuel did you have when it stalled? Members been having problems with their the pickup tubes (supply line) in the tank getting pin holes in them (usually 25 % from the end of tube but they could be a higher %.
But stalling and hard to start sounds like air in fuel system (hoses with airline cracks loose fittings....

 

[Missouri Mule]

If it dies out again take your fuel cap off and see if it starts.

Several members had trouble with engines dying. They took their trucks to Cummins where the tech found the engine speed sensor/crank speed sensor was acting up
Causing stalling but eventually they were sble to restart the engine. Your problem?.

How much fuel did you have when it stalled? Members been having problems with their the pickup tubes (supply line) in the tank getting pin holes in them (usually 25 % from the end of tube but they could be a higher %.
But stalling and hard to start sounds like air in fuel system (hoses with airline cracks loose fittings....

 

[BFurton]

Thanks GAmes and Mule!
Been thinking about several things, one is 'what's inside the tank' - is the fuel module/in tank filter still good? Is there any sludge/algae/crud in there? Draw straw as well, is it still good?

When it happened this time, again I was @ > 3/4 tank. I remember still having +22 psi fuel pressure as I coasted to the side of the road, at least until the transmission unlocked as it was still turning the engine - once the transmission unlocked @ 35 MPH, stone cold 0 psi.

I will have to add testing of the speed/crank sensor into the plan - as that would explain a lot more than just air in the fuel - as I have not had a "hard starting problem" at all (except when this has happened). Priming has taken care of it so far, but it could be that letting that sensor cool off or whatever might be a reason that it resarts after I've primed it and I'm only assuming that it is a fuel related problem rather than a 'sensor'/'electrical' problem.

Traveling home tomorrow with 5th wheel in tow. Less than 150 miles, so fingers crossed!

Thanks again Bill!!

 

[GAmes]

The engine speed sensor on a 12 valve will not affect if it runs or not. You could disconnect it entirely, the only affect would be no tach, no charging and no cruise control.

If you don't have anything mounted in the bed like a 5er hitch or an aux fuel tank lifting the bed to pull the canister is likely the easiest. Don't forget to unplug the tail light wires.

 

[BFurton]

Thanks GAmes... I do have a 5th wheel hitch installed in the bed. It is a Reese Signature series 18K hitch. Removing the 4 bolts that hold the pucks in isn't a problem. I was thinking that I could undo the forward bolts and remove them. Loosen the rear ones enough to jack the front of the bed up enough to get at it. The rear ones would hold the bed from sliding backwards. In another post, someone used a back hoe the pull the front up and it looked like he had left the rear ones in....