got a brain teaser

[notchsleeper80]

ok guys, need some help here. got a 99 ps 7.3 that runs and drives great, no leaks, no smoke, no abnormal anything. the truck does great on fuel mileage almost all of the time. but out of nowhere it will suddenly burn through fuel like theres no tomorrow, then, it clears up and gets better again. I get fuel from the same place an evyone i know gets it there with no problems. any ideas

[hotairgypsy]

first question i would have is did u check the codes in computer...the computer stores codes without setting off dash warning lights

[7.3Lariat]

Someone is stealing your diesel!

[notchsleeper80]

i have checked codes, did koer and koeo self test, watched all sensors and regulators, all is normal. I filled it up this morning and drove 55 miles exactly, and it is now below 3/4 of a tank, normally upon fill up it get about 90 miles til i hit 3/4 of a tank. all fill ups are the same as far as how much i top it off. always til i can see fuel in the neck

[notchsleeper80]

i know thats not an exact science but its definately not 40 miles difference in fuel

[floorboy]

Are you running a winter blend or straight no.1 by chance?

[jesilvas]

Ebpv sticking possibly.
maybe even brake caliper sticking

I made my Samsung SGH-I997 send this.

[notchsleeper80]

just regular no 1

[Justin@DP-Tuner]

Are you calculating this by hand or just going by what the gauge says?

If you are just going by what the gauge says then that may be your issue. That thing is never accurate.


Sent from my iPhone using AutoGuide.com Free App

[hydroman]

If all else is the same runig wise, power, smoothness ETC I agree with 7.3 Lariet. Get a locking fuel cap