TRUCK STALLED A FEW TIMES THIS MORNING

[bagpiperjosh]

When i got to work this morning my truck stalled going up a small grade at low rpms. I started it and it stalled again. Then i started it once more and gave it a bunch of fuel and had to let the clutch out real quick so it wouldnt stall. and i got it a little further. then it stalled on a flat surface.

I started it again, and it seemed to idle ok after i backed it in to a parking spot.

A few things to note

This morning my truck did seem to be surging a bit ( like jerking back and forth) on lower rpms.
I have been running an unknown amount of gas mixed with diesel that a customer put in her prius at the gas station. ( a prius only holds like 10 gallons of fuel, so i cant imagine its any more than 5 gallons of gas.) and the rest of the tank is waste oil

so at the most, I might have 5 gallons of gas in a 20 gallon tank.

I have never had any issues with air intrusion since i changed the IP and return lines, so i feel that's unlikely.

I have upgraded my water separator so i dont know how likely water could be getting in there, ( the water separator filter has less than 1000 miles on it.)

any ideas?

i dont think i left any important details out

thanks!

 

[stumiister]

Do you have a mechanical lift pump on the side of the block?
Do you have good fuel pressure at the schrader port on the fuel filter head?

 

[bagpiperjosh]

Do you have a mechanical lift pump on the side of the block?
Do you have good fuel pressure at the schrader port on the fuel filter head?

yes, mechanical. and i dont know.

edit: new mechanical lift pump

 

[lotzagoodstuff]

Your truck might have been sucking air from physically running out of fuel. Remember if you are low on fuel (or if you're shower head has disintegrated/fallen off) and you are going up or down, you can easily suck air. You're fuel cocktail sounds like it could also be the culprit, as it simply an unkown. If it was me, I'd put about 5 gallons of fresh diesel in it and see if it's better/same/worse.

Good luck

 

[icanfixall]

We have two fuel tanks on these rigs. Can you run off the other tank and whats in that tank. A fuel cocktail might be the obly reason for the stalling. If you are running out of fuel the vacuum switch on the fuel outlet side of the filter should have lit up on the dash.. At least I feel it should have lit up...

 

[bagpiperjosh]

We have two fuel tanks on these rigs. Can you run off the other tank and whats in that tank. A fuel cocktail might be the obly reason for the stalling. If you are running out of fuel the vacuum switch on the fuel outlet side of the filter should have lit up on the dash.. At least I feel it should have lit up...

im thinking the fuel mixture is bad... i replaced the scrader valve and it started and idled fine. then i went to home depot and on the way, it stalled again on the highway. after trying to start it numerous times it finally started againg, then i switched to the rear tank. it has been fine ever since..

but heres what i dont understand

I drove 4 days on the front tank with no problems.. how is it all of a sudden giving me problems?

 

[icanfixall]

Maybe a suction problem causing the fuel shortage to the injection pump.

 

[79jasper]

I would bet the gas knocked something lose, in turn clogging something.

 

[homelessduck]

25% gas is on the high side. Your problem sounds similar to a recent problem I had. It ended up being a clogged fsv. After removing the tanks I found the pickup screens broken into small pieces. I'm assuming that is what clogged the fsv. I would drain the fuel in question and put it in the tank that you aren't having problems with. If it stalls again then its your fuel. If it doesn't it is an issue with your tank-fsv.

 

[GOOSE]

Adding gasoline takes away from the lubricity of the fuel. 25% is a high amount of gasoline even mixed with wmo. You may have issues with your IP such as a sticky metering valve. I would drop the tank and look at the sump, get rid of the bad mix, at least scavenge it and use it with some good diesel. This sounds like the typical "changed more than one variable so its hard to diagnose" situation.

 

[bagpiperjosh]

ok, ive been running on my rear tank for some time now(pretty much straight diesel). and the truck is still stalling, mostly up hills and under heavy acceleration, (which usually go hand and hand) it will start to buck a bit, then usually stall. it takes a few tries to get it started again too. but i have not had ANY problems at idle. is this a sign of a bad fsv?

 

[79jasper]

Bad? Not necessarily.
Partially clogged? Yes.

You could try running some compressed air through from the front. Say 20psi or so.

 

[franklin2]

ok, ive been running on my rear tank for some time now(pretty much straight diesel). and the truck is still stalling, mostly up hills and under heavy acceleration, (which usually go hand and hand) it will start to buck a bit, then usually stall. it takes a few tries to get it started again too. but i have not had ANY problems at idle. is this a sign of a bad fsv?

Going up hills and heavy acceleration is when you are using the most fuel. So you can be pretty sure it's fuel starvation I believe. Now to find the problem.

 

[bagpiperjosh]

if it were bad, would it cause both tanks to make my truck run crappy? the front tank is far worse though.

or if it were clogged, could it do that to both tanks?

 

[GOOSE]

I agree, you are starving for fuel. I had a kink in the rubber line that feeds the lift pump. It caused the exact conditions that you are describing. Talk about being white knuckled going over the Walt Whitman Bridge!! A new piece of 3/8 line solved the problem. I actually fixed it in Subway's driveway before my trip back home. I would be looking for a similar condition.