Fuel System Problems

[keefer]

Still havent managed to find the issue with my truck. it starts and warms up fine but loses power and dies after a few minuets of driving or about 15 minuets of idling. I have replaced all the rubber lines, sending unit filter, entire fuel filter unit with a napa spin on, injector pump, fuel pump, and all the old diesel. fuel shuttoff solenoid seems to working as it makes a click when tested.
its been over seven months since this thing has been used as a daily driver. Anyone have any insight? riding a motorcycle in december isnt much fun, can someone help me get this thing back on the road?

 

[Asmoday]

Man...I sure hope someone can steer you in the fix it direction. I would have gone insane by now...

 

[AlexFolino]

Any signs of air in the fuel system? When the truck shuts off does it just flat out die or is it a slow stumble? Will it fire back up after stalling?

 

[cpf240]

Silly thought alert - What about a build-up of back-pressure in the exhaust system? Maybe someone built a nest in the mufflers. I've also heard of the material inside the muffler breaking down and causing a blockage.

 

[hotdogs151a2]

Mr. keefer:
Several years ago I got stuck driving my motorcycle in the winter, you are correct no fun at 28 degrees.
Have you tried cracking the fuel cap? It sounds like the tank may be building pressure or vacuum and over powering the mechanical fuel pump. I will keep thinking about your problem.
Thanks, Pvt. Hotdog

 

[Blue2actual]

MAYBE try an electrical fuel pump? not too sure what else to check as it seems you have replaced 95% of the fuel system. I got a 6-8 psi pump at advanced auto for 45$ and it has lasted me over a year and still pumpin' just fine

 

[corelokt]

Try a process of elimination. Find a small boat type fuel tank made of red plastic usually. Fill with diesel and connect it directly to the fuel pump. Does it work now? If not, test the fuel pump with a standard fuel pump tester, actually a vacuum / pressure tester available about everywhere. If not that, put some diesel cleaner additive, or 2-stroke oil, in the red plastic tank. Keep running that as much as it will. Did it improve? Pull the air cleaner, look for mice nests, seriously. Cut the exhaust in front of the mufflers. Make it a clean cut. Does it run? There are "Band clamps" for exhaust that will reconnect the pipes easily, so make it a clean and straight cut. If not that, replace the fuel pump if you did not. Then the injectors or injector pump would be my next thought. Good luck.

 

[reloader64]

My wife's civvy CUCV had the same problem. I replaced everything except the injector pump, and added an electric fuel pump. It finally became non-drivable, but ran fine with a 2 gallon portable tank under the hood, hooked directly to the lift pump. After much thought, I drained and dropped the fuel tank, and removed the fuel pickup and float assembly. The filter sock in the tank is black, and is obviously restricted. Purchased a replacement sock, and will replace it after I walk the dog, and stop fooling around on SS. I'll let you know how it turns out.

Scott

 

[keefer]

@reloader64, i replaced that filter sock already and seems to still be fine. i have pulled the sending unit several times to check it since and everything seems fine. almost seems like it might be electrically cutting off fuel at the injector pump.

@ corelokt, ill definitly try cutting the exhaust off and checking it out. maybe the mufflers have a lot of rust in em. the rest of the exhast is one big piece of rust so that would make sense.

@Blue2actual. i replaced my fuel pump once already. do you think its possible it has gone bad so quickly?


@AlexFolino, it stumbles a little bit then dies. i dont think its an air problem. it will fire back up with a lot of cranking. if i let it sit a while, it will fire up and it will run fine for a bit, then stumble and die again

 

[keefer]

cutting off the mufflers revealed nothing other than all the holes in the system. nothing in the air cleaner assembly either.
Im wondering if having all the wires disconected from the stock fuel filter is giving me problems? any thoughts?

 

[reloader64]

So I replaced the sock, put everything back together, primed the fuel filter, and fired her up! She idled like a champ....for about 5 minutes, then died. I took the electric pump out of the loop, primed, started, and drove it around for about an hour. No problems. I thought that maybe the rubber hoses that I ran to the electric pump had softened a little with age, and kinked enough to restrict flow. Further evaluation revealed that the problem was, the (6 month old) electric pump was making noise, but not pumping. The truck is still occasionally hard to start (the original reason for the electric pump), so I guess I'l pull the intake and replace the hoses and pipes that I haven't replaced already. Plus, I discovered that the oil pan gasket is leaking like a sieve. Looks like a have a busy weekend coming up quickly.

Scott

 

[idM1028]

Im wondering if having all the wires disconected from the stock fuel filter is giving me problems? any thoughts?

It shouldn't. To the best of my knowledge those wires are for the fuel heater (two wires on top of base) and the fuel pressure sensor for the STE/ICE. If you could find somebody with the equipment to run a diagnostics test that MIGHT help you out, but I think there's all of 3 guys that fit that description on SS.
Honestly, it almost sounds like you might have a bad injection pump. From the sounds of it, it's about the only thing you haven't replaced yet...

 

[cpf240]

It shouldn't. To the best of my knowledge those wires are for the fuel heater (two wires on top of base) and the fuel pressure sensor for the STE/ICE. If you could find somebody with the equipment to run a diagnostics test that MIGHT help you out, but I think there's all of 3 guys that fit that description on SS.
Honestly, it almost sounds like you might have a bad injection pump. From the sounds of it, it's about the only thing you haven't replaced yet...

And the water-in-fuel light...