Faulty Fuel Solenoid??

[LT67]

Riddle me this...

I'm driving the 86 M1008 just cruising along at 55mph and the engine suddenly dies. It was like turning off the key, but the dash lights were still on. The engine would not refire. I pulled the pink wire going to the fuel solenoid with the key on and I could hear the solenoid clicking. I loosened the air bleed screw on the filter housing and fuel sprayed out. This AM I go outside with the intention of cracking open an injector line to see if it was getting fuel and it fired right up. As of now it's idling in my driveway. The engine is not missing on any cylinder.. all is normal.

Any ideas??

 

[cucvrus]

The only thing it could be is an interruption in fuel delivery. With out seeing the vehicle it will be hard to diagnose from afar. You mention it shut off. Have you ever pulled the fuel tank and checked the fuel sock filter on the end of the tank? It could be it clogged and shut off. Then after the pressure was released the debris released and the lift pump was able to suck fuel again. I seen some nasty stuff in the fuel tanks. One I remember was filled with tan flaking paint chips and peelings from the inside of old steel military fuel cans that the owner was using to refuel so he could burn heating oil. I am talking lots of tan paint clogged the fuel sock. The old metal fuel cans were known for this. Worth a look at the inside of the fuel tank if you have never been in there. Good Luck. Report back on your findings. In all the years and thru many repairs I have never had a injection pump solenoid/switch fail Call me Lucky but I never had many of the issues that posters have here on this site. Luck or just good maintenance have prevailed over my many years and miles of CUCV ownership. Be Safe.

 

[LT67]

The only thing it could be is an interruption in fuel delivery. With out seeing the vehicle it will be hard to diagnose from afar. You mention it shut off. Have you ever pulled the fuel tank and checked the fuel sock filter on the end of the tank? It could be it clogged and shut off. Then after the pressure was released the debris released and the lift pump was able to suck fuel again. I seen some nasty stuff in the fuel tanks. One I remember was filled with tan flaking paint chips and peelings from the inside of old steel military fuel cans that the owner was using to refuel so he could burn heating oil. I am talking lots of tan paint clogged the fuel sock. The old metal fuel cans were known for this. Worth a look at the inside of the fuel tank if you have never been in there. Good Luck. Report back on your findings. In all the years and thru many repairs I have never had a injection pump solenoid/switch fail Call me Lucky but I never had many of the issues that posters have here on this site. Luck or just good maintenance have prevailed over my many years and miles of CUCV ownership. Be Safe.

Something caused an interruption in fuel delivery, not sure what it is. I did drive the truck this AM to run some errands and all was well. IDK what caused it to stop running yesterday.

 

[cucvrus]

That interruption in fuel delivery may be impossible to duplicate again. That is why I suggest a look see in the fuel tank. That screen may never clog shut again. But until you eliminate that issue as the cause you may never know and it could happen again at any moment. Finding a no run issue is a process of elimination. Start at the source (Fuel Tank) and work your way forward. Good Luck. Replace all the rubber fuel lines as you go. Use rubber braided fuel line not clear plastic hose.

 

[LT67]

That interruption in fuel delivery may be impossible to duplicate again. That is why I suggest a look see in the fuel tank. That screen may never clog shut again. But until you eliminate that issue as the cause you may never know and it could happen again at any moment. Finding a no run issue is a process of elimination. Start at the source (Fuel Tank) and work your way forward. Good Luck. Replace all the rubber fuel lines as you go. Use rubber braided fuel line not clear plastic hose.

Yes, pulling the tank and seeing what's inside is on the list... lol, when I bought the truck the owner thought the motor was toast because his ex poured sugar in the tank.

 

[U1100L]

Lift pump

 

[LT67]

Lift pump

New lift pump and I loosened the air bleed screw to see if fuel was going through the filter. Fuel was spraying out the top and side nozzle.

I drove the truck 66 miles yesterday and it didn't miss a lick. It ran like it normally does

 

[cucvrus]

You are sure you have the correct lift pump? Not sure if you know but several will fit on the 6.2 but are incorrect. They are listed as correct in parts manuals but do not pump fuel correctly. Also motor mounts can sag and allow the engine to rest on the rubber feed hose on the bottom of the lift pump. This will cut a small hole in the feed line and may just leak air but it will interrupt the fuel delivery. Just check these things closely. Good Luck.

 

[LT67]

You are sure you have the correct lift pump? Not sure if you know but several will fit on the 6.2 but are incorrect. They are listed as correct in parts manuals but do not pump fuel correctly. Also motor mounts can sag and allow the engine to rest on the rubber feed hose on the bottom of the lift pump. This will cut a small hole in the feed line and may just leak air but it will interrupt the fuel delivery. Just check these things closely. Good Luck.

Yes, it is #chfp906...... already went through the parts store sending #mf30030 and it didn't work.

Ran a few errands in it this AM and it hummed along per usual. I'm stumped as to what caused the fuel flow to stop

 

[cucvrus]

Clogged fuel sock. It may never happen again. But until you look and eliminate that as the issue that is where I would look. First place for fuel supply and a known problem on older vehicles. Think about this. New Chevrolet gas trucks do not have a fuel filter. Everything is filter thru the pickup screen. It can't run thru the electric fuel pump it never has a chance to get that far. it works because our 2016 GMC has 170K and never had the fuel pump out or any fuel issues. Diesels are still filtered. Good Luck.

 

[U1100L]

Huh, Well, I went throught 4 mechanical lift pumps then gave up and went electric. Can't beat electric pumps for cold starts.

6-8 PSI will keep them happy. I run a Garber spin on from the local plumbing supply Co. and can now install gauges. Piece-o-cake to prime.

Put 85K on the truck with that set up.

IP seals dried out and leaked about 20K miles ago other than that it has been very loyal.


In short, I'd blow back into the fuel tank 120PSI teach that sock whos boss! (to be polite) Don't forget to take off fuel cap!!
Then install electric pump, a gauge and spin on fuel filter assembly. That takes care of fuel delivery problems.

 

[nyoffroad]

Yes, pulling the tank and seeing what's inside is on the list... lol, when I bought the truck the owner thought the motor was toast because his ex poured sugar in the tank.

Your driving it after sugar was put in the tank?

 

[LT67]

Your driving it after sugar was put in the tank?

Yes.... sugar has no effect on diesel. It just gets caught in the fuel filter

*I've put 10k miles on the engine after all of the sugar eventually got out of the tank

 

[cucvrus]

I was always told my CUCV was SWEET. told

 

[ehuppert]

story at the shop i worked at.... Local good old boy had a truck which from time to time would die, then promptly restart. After a year of intermittent issue finally dropped tank and investigated. Well, the foil from the top of a dry gas bottle was swimming around in there. Would cut off fuel, then when motor stalled suction would release and foil would drop.....

Moral: Drop the tank and eliminate debris as an issue. And if tank is crappy in or out, replace.... Tanks apx $100.....

 

[Keith_J]

Did you suddenly let off the throttle and it died? Sticking metering valve. It slams shut in such conditions under the force of the fly weights, then the idle spring force is the only thing which can pull it open.

 

[LT67]

Did you suddenly let off the throttle and it died? Sticking metering valve. It slams shut in such conditions under the force of the fly weights, then the idle spring force is the only thing which can pull it open.

No, I had my foot on the skinny pedal maintaining 55mph and it just stopped running

 

[LT67]

Since the truck died on me I've put 200 miles on it and it hasn't missed a beat. I did change the fuel filter just to be on the safe side.

 

[cucvrus]

OK. But did you discover the issue. The fuel tank must be dropped to assure that the issue is resolved. Dancing around the issue will not fix it. It takes time and energy to make a definite repair so this does not happen when you are miles from home and end up stranded along the road with a huge towing bill. In my life I was only towed once. That was when I had a 1968 Camaro SS396 and had it jacked up with HI jackers and 50 series tires on the back. I had bicycle tires on the front and went around a turn in a development and the upper ball joint broke. HA imagine that. I truly hacked that car to pieces and destroyed it. It would be worth about $50K today. Who would have know. But truly you need to drop the tank.

 

[LT67]

When the engine

OK. But did you discover the issue. The fuel tank must be dropped to assure that the issue is resolved. Dancing around the issue will not fix it. It takes time and energy to make a definite repair so this does not happen when you are miles from home and end up stranded along the road with a huge towing bill. In my life I was only towed once. That was when I had a 1968 Camaro SS396 and had it jacked up with HI jackers and 50 series tires on the back. I had bicycle tires on the front and went around a turn in a development and the upper ball joint broke. HA imagine that. I truly hacked that car to pieces and destroyed it. It would be worth about $50K today. Who would have know. But truly you need to drop the tank.

Yes a 35yr old tank needs to be cleaned out. What I'm not getting is when the engine cut out, I loosened the air bleed on the filter housing and fuel was spraying out the top. Still wouldn't start back up. So that tells me fuel was getting through the filter. At the time I didn't have any tools with me so I could crack open an injector line to see if fuel was coming through.

Regardless, as soon as the fuel in the tank runs low, the tank will get dropped to see what is inside of it.