first of all, this is on a '89 f-250 with a 7.3 idi. also, it is cold here. single digits/below zero...
i was taking the truck for a short spin after fixing something completely unrelated. i started it, idled for like 10 minutes, drove for like 10 minutes, then...
the "fuel filter restriction" dummy light came on, and about 5 minutes later, just as i got it parked, it stalled and wouldn't start again.
i have dieselkleen (white bottle for winter) in the fuel. i have been meaning to change the fuel filters for awhile but i'm pretty sure this sudden stall is related to an unusually cold weather spell.
this morning i plugged the block heater in for 2 or 3 hours and then tried to start again. noticed that with the ignition on, there is a buzzing/humming noise which seems to be coming from driver side frame rail right by the front edge of front fuel tank. the truck has dual fuel tanks, and this noise changes pitch when i flip the tank selector switch (this is all with the engine off but the ignition in start). I was wondering if the noise I described could be the fuel selector switch valve? Or if it's just related to the filter being iced/clogged or something? Should I change the filter then see if the buzz goes away? The noise is not the fan/blower or the block heater. With the ignition on, i can hear blower (on low), glow plugs cycle as usual, dinging, all normal PLUS this louder buzz/hum coming from frame where i described.
I am also stumped as to how there could have been a cold weather related fuel problem like wax/ice/gelling because i have dieselkleen in the fuel. especially after running for 15-20 minutes "just fine". One thing i thought of was checking if the fuel filter heater in the filter header is working. My truck does have one, right? I can't check for heat because the truck won't start. In this picture, which of the 2 electrical connections is the fuel heater? (PICTURE 1
) Also, i found a smaller electrical connector (looks like its for a sensor or something) that is just dangling. I think it's the water-in-fuel light connection but i could be wrong. (PIC 2)
Finally, is it stupid to just change the final filter (under the hood), not the frame mounted one as well? Also, does the "fuel filter" light pop on for just the final filter, or for either one, or for any fuel supply problem?
Thanks for reading! maybe i just need to change the filter, or get some of that diesel 911 stuff into the fuel system or something, but i thought i'd get the right info before doing anything.