weird fuel issue and stalling
Senior User
Joined: Jun 2010
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From: NW Ga
Sorry got distracted and didn't see your last post. I have had problems with air getting into my fuel system. It would make it hard to crank etc. I never had high rpms at idle but on the mornings when it didn't want to crank i would start off from my house and all of a sudden it would act as if someone else had just punched the pedal for a second or two and would sound as if someone had traded my idi for a powerstroke and the engine would get that loud powerstroke rattle and then just ease on back down. This is after I had backed out of my drive and rolled 1/8 of mile downhill to red light. It always happened when i got on the gas coming out of the red light. I figured it had something to do with air trapped in the system that was finally passing through. Not sure if this is what you have but if you let it idle or give it a little bit more fuel maybe it will pass the air through the system. Does anybody know how air affects the injector pump?
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Senior User
Joined: Jan 2009
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From: Southwest Florida Coast
yea, I was checking the sensor thingy, thought it was the fss?lightbulb! it was the TPS doh! right thing wrong name. just took it for a test drive and did fine for about a mile and then she bucked and died. bled air out of filter waited and she started right up, drove home and she died in the driveway while I was checking schrader valve. No fuel coming out of valve while engine running, engine shutoff, 1/3 pt in 10 seconds. should there be fuel outflow from valve w/ engine running?
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Senior User
Joined: Jan 2009
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From: Southwest Florida Coast
Star, the mechanical pump is no longer connected, but I am starting to rethink that. Can you explain to a wiring hater how to hook up the switch to the E-pump? I've got it hooked up with a relay to the FSS so it comes on when I turn the key.
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Joined: Oct 2007
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From: Faibanks Ak.
Some install a pump, just to prime the system when you change the filter, I have myself and just hooked the pump up on a toggle switch. The one I did this on was my company pickup and was one of the first chevys, so I did this to save on the starter. lol
If you do this you need to make sure fuel free flows through the pump with it not running.
Most e pumps are not designed to suck and need to be placed on the frame as close to the tank as possible, in your case just after the tank selector valve.
It does sound as if your pump is running out of fuel, either it can't keep up sucking that distance, or your hose on your sending unit is sucking closed or to the bottom of tank, or even a slight air leak between the tank and pump will let it suck air instead of fuel.
If the tank is not venting it will cause it to run out of fuel too.
If you do this you need to make sure fuel free flows through the pump with it not running.
Most e pumps are not designed to suck and need to be placed on the frame as close to the tank as possible, in your case just after the tank selector valve.
It does sound as if your pump is running out of fuel, either it can't keep up sucking that distance, or your hose on your sending unit is sucking closed or to the bottom of tank, or even a slight air leak between the tank and pump will let it suck air instead of fuel.
If the tank is not venting it will cause it to run out of fuel too.
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Joined: Jun 2010
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From: NW Ga
Fuel should come out of schrader valve. You have air in the filter. It has to be coming from somewhere!!!
The air in the filter tells me that its getting air some where or e pump isn't keeping up and injector pump is sucking what little it can out of filter and air is getting in around filter or else the pump couldn't pull the fuel out. If the pump is working at high enough pressure then your leak should be before it cause it should create enough pressure for you to see something leaking somewhere
You could pug the intake hose in solid fuel line and without a hole in it somewhere the pump would not be able to suck the fuel out or air in. Is your filter leaking? Bad e pump? Run e pump to gallon jug of diesel to eliminate lines to tank and tank pickup. If it runs fine its in the line to the tank. If its from e pump to motor you should have more problems. You could go to your hardware store get some clear vinyl tubing and start substituting it for sections of your fuel line and look for bubbles. I did this to find a leak that was so small it didn't leak fuel just air and only caused problems when it set for more than a day. I had to leave it on for days to figure out where the problem was.
The air in the filter tells me that its getting air some where or e pump isn't keeping up and injector pump is sucking what little it can out of filter and air is getting in around filter or else the pump couldn't pull the fuel out. If the pump is working at high enough pressure then your leak should be before it cause it should create enough pressure for you to see something leaking somewhere
You could pug the intake hose in solid fuel line and without a hole in it somewhere the pump would not be able to suck the fuel out or air in. Is your filter leaking? Bad e pump? Run e pump to gallon jug of diesel to eliminate lines to tank and tank pickup. If it runs fine its in the line to the tank. If its from e pump to motor you should have more problems. You could go to your hardware store get some clear vinyl tubing and start substituting it for sections of your fuel line and look for bubbles. I did this to find a leak that was so small it didn't leak fuel just air and only caused problems when it set for more than a day. I had to leave it on for days to figure out where the problem was.
Junior User
Joined: Dec 2011
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From: Reddick,Fl.
Why not put fuel pressure on it see what the pressure at idle , when get on and what is when just drive study. I know on my 6.5 Chevy the LP would get weak and truck would act up. harbor freight sell a vacuumm / fuel gauge tester cheap Just maybe when getting on it your e-pump can't handle pressure you need
Fuel Pump and Vacuum Tester
Fuel Pump and Vacuum Tester
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yeomansjon
1999 - 2003 7.3L Power Stroke Diesel
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May 24, 2011 06:42 PM
