Intermittent Fuel Problem?????

[Kornstad]

My 1992 4wd Club Cab w/manual trans has developed a intermittent problem where it is acting like someone is turning off the key switch!! I'll mash in the clutch to keep it from lurching and it seems to catch itself and idle fine! I let the clutch out and it may repeat itself or act as if everything is "OK" Any suggestions

 

[Greenleaf]

So when you remove the load from the engine, (by pushing the clutch peddle down) the engine then runs ok untill your re-engage the clutch? Then it will sometimes act normally and sometimes not?



I have been troubleshooting the same problem on a school bus.

 

[Kornstad]

Sorry it took so long to reply. The answer to your question is "yes" you mash in the clutch and it idles fine let it out and start to accelerate and it acts as if the fuel shut off solinoid looses it's power!!



Dan

 

[Doc Holiday]

my truck kept "running out of fuel" even though I knew it was full. I had to replace the fuel pickup and sending unit in the tank to the tune of $315.



I tried everything else but the fuel lines first though. I knew it wasn't my injection pump as the sucker that sold me my truck had just put a new one on it.



If this is your problem let me know, I will be curious to see if you wind up with my newest problem too.



If it sits for like 2 hours sometimes it loses prime.

 

[pepecat]

is losing prime a problem indicating a ve pump going south, or leaky injectors? I have had rough idle and starting in the mornings lately and it hasn't gone away with a new fuel filter full of injector cleaner upon install with more cleaner in the tank. One time after towing long and hard I pulled off the road for dinner, let it cool down of course till below 300 at idle, but when I returned it wouldn't start. It took a good 10 seconds of cranking to kick over, and then it was fine. lost prime for some reason, to be sure, the fuel shutoff solenoid wire couldn't have just popped back on... I also loose fuel pressure to the ve on semi hard accelerations, and figure it's lift pump related. I hope the piston lift pump solves all the idle and wot problems.

 

[RWWinslow]

I have battled a similar problem occasionally over the years. . . . check the rubber fuel line that goes from the steel fuel line on the frame rail to the lift pump on the side of the block. If it looks damp it is leaking enough air while the engine is running to cause all of the above mentioned symptoms. Regular fuel line and cheap hose clamps will not work - you need to use marine diesel fuel line or buy the expensive multi-fuel / fuel injection rated fuel line and then use premium hose clamps. Good luck.

 

[pepecat]

thanks for the advice, I'll do some inspecting of fuel line and we'll see... sorry for hijacking the thread

 

[Mel Fuelling]

Small air leaks can be tough to find. I pressurize the fuel tank with a spraygun regulator, set under flow to 10psi. The regulator is connected

with 3' of 1/4" air hose to the inside half of a fuel cap. Then snap on an air supply hose and use a nice bright flourescent trouble light to look for pinhole fuel leaks. If your lift pump has quit, the vane pump in the IP is pulling a vacum all the way to the IP. After you pressurize the fuel tank, all air leaks turn into fuel leaks.



Good Luck,

Mel