help and advice, please!!

a couple of nights ago as i was driving, my low fuel warning light came on, where it normally does at about 1/8 of a tank. i know i shouldnt let it get that low, but occasionally it happens. about 2 minutes later i am stopped at a light and the truck dies. i shut off the key, turned it back on, and no "wait to start" light . i tried cranking it over and could tell immediately it wasnt gonna start. so, i jumped out and got it pushed to the side of the road. sitting there messing around i couldnt hear the pumps cycle when i turned the key on and off. opened the filter canister - it was about half full of fuel. did the key on and off 3 times = no codes, just "p done". there was a gas station across the street, so i went and got five gallons of fuel and put it in the truck. (gauge went to just over a 1/4) cranked it over for about 15 seconds two times - nothing. again a third time, and the truck fired. so, i headed for home, about 5 mile away. truck ran fine all the way. i got on it once and it still ran great, normal boost, egts, power. no sputter or lag of any kind......

so, some ??'s :
1 - what the heck happened???? i just had a new sending unit put in the tank about 1 year ago. can they go bad that fast? (not much time to react if your already dry when the light comes on....)
2- if the lift pump is toast, would there still be fuel in the filter? or would the IP suck all that out?
3- why no "wait to start light"
4 - does "p done" mean no codes found?
5 - can the IP pull fuel thru the lines to keep the truck running even if the lift pump is toast?

sorry about the length. thanks for all help.
oh yeah, a FP gauge will be going in the truck immediately too!

 

1 - what the heck happened???? Might have a ground fault, or bad sender (new senders can be bad too, or perhaps even a sender for the wrong size tank. You can check the Ohms on the sending unit to figure out operation, but this most likely would require that you remove the tank. Might as well bring back the truck to whomever replaced the sending unit. <shrug>.

2- if the lift pump is toast, would there still be fuel in the filter? or would the IP suck all that out?
Gravity and IP would need to draw the fuel, but perhaps there is not enough pressure to sustain smooth operation. An IP can sometimes run for a while without a lift pump, but its detrimental and will eventually fail. I'm guessing that if your transfer pump is bad and you have a loose cap on the filter housing.

3- why no "wait to start light" Because the motor is warm?

4 - does "p done" mean no codes found? Means its done reading codes, if no codes flash, then you see p done it means no codes.

5 - can the IP pull fuel through the lines to keep the truck running even if the lift pump is toast? Yes... are you sure your lid was on tight enough for the filter housing? Maybe some air got in there because the IP is drawing the fuel. Did you notice any varnish around the "can" that might indicate a leak? Your pickup connection might also be drawing air and this is building up in the filter can (being the highest point in the circuit).

You're on to something with that gauge. I've had a part-timer that I'd been using during lube service to check the pressure. I just recently got a full-time gauge for inside the cab.

 

thanks for the reply burner.

5 - can the IP pull fuel through the lines to keep the truck running even if the lift pump is toast? Yes... are you sure your lid was on tight enough for the filter housing? Maybe some air got in there because the IP is drawing the fuel. Did you notice any varnish around the "can" that might indicate a leak? Your pickup connection might also be drawing air and this is building up in the filter can (being the highest point in the circuit).

yes the lid was on tight - i had to put a wrench to it to get it off. no sign of any leakage around the can.

if i'm not pullin any codes, does that mean (mabey) my LP and IP are okay?

anyone else have any ideas???

 

No problem buddy... Sorry I could not be of more help.

Here's a bump, and another suggestion:

I'd try to figure out where all the air came from. If you check your filter now, you see that there is no air, right?
Get that fuel pressure gauge to know if the transfer pump is doing its thing.

I suppose you could dip your tank to see if the sender was feed'n you BS.

Good luck

 

Get an in cab fuel pressure guage, keep your tank 1/2 full at all times around town. This is not a gas engine and does not like air in the fuel system.

If you have no working LP there is nothing to "flush" out air when your pickup gets below the fuel level or picks up air bubbles from the fuel level being so low. Keep your tank 1/2 full at all times around town. It helps keep air out of your fuel system.

Yes, the IP can suck fuel to keep you running, but there is no fuel to cool the IP, so it will burn it up.

Get a FP guage.

 

If you would like my 2 cents, sounds like you ran out of fuel! plain and simple. just because the gauge said an eigth of a tank doesen't mean its accurate. seems like you should have the sending unit on that fuel gauge checked or the dash gauge itself. simply put, if it were my truck i would fill up and never let it go under half a tank! Good luck!