89 ford f250 question.

a buddy has a 89 f250 with a 5.8. it idles fine, but as soon as you step on the gas it dies.

I am thinking its a fuel prob. it has the duel tanks and it does not matter which tank you use on the switch.


what PSI should it run at? is there a way to check the fuel pressure regularor? it has a vaccum line on it, can i remove it and apply vaccum and see if it changes?

there maybe a shrader type test port on the fuel rail. pressure should be 37+psi if memory serves.

Original in tank pumps?

CLEAN the MAFS mass air flow sensor . Do this before you start replacing any parts .

The tiny wires must be cleaned and dried, then reinstall and test again .

If it still dies out, try opening the throttle 'really slowly' and see what happens . Rapid throttle opening can be a bad TPS throttle position sensor .

on recommendation from a neighbor I pulled the collection bowl from the tank switch valve. it was full of crap. cleaned that up real good. truck runs loke a top now.


I thought it was really, really odd, both lift pumps went bad at the same time.