I Know just leave well enough alone.

Here's the problem: This truck has had a loss of power problem (right from the factory) on and off for approx 2 years. It'll have a fit and be over it like nothing ever happened. Now within the last few days it has progressed and this is the worst the truck has ever acted. Tried the Ford test of the ICP and it passes to a point, hold it at 3400 rpm for 3 minutes and watch the pressure to not exceed 1250 psi. Well, it doesn't exceed the pressure limits in the test mode, but try and road test, and I seen pressure as high as 3600 psi. The truck will not get out of it's own way!!! I mean smashed to the floor she's killing cylinders and just plain will not go. I tried a new IPR valve that I keep as a spare, and I did throw in a new fuel filter cause it was almost due anyway. I checked fuel pressure and at idle has 46.5 psi Fords window is 30-80 psi, but at WOT pulls down to 00.0. Now you'd think fuel pump, but switch the tank and same exact thing to a tee. Oh almost forgot, Ford tried blaming it on the Amsoil saying it was becoming airiated, so just for fun, (the oil was just changed 1800 miles ago), I cleaned a drain pan and drained the Amsoil back out and dumped in three fresh gallons of Rotella. Not a difference made.

What am I missing?

Maybe a bad switching valve? Maybe BOTH screens are blocked in the lift pumps? Anybody that HAD a PS that had the same or similar probs?

The truck is a 97 F350 SRW crew cab long box 4x4 with 80,000 miles

Thanks Rick

 

Sounds to me like a plugged fuel regulator. Try cleaning your screen in the bottom of your fuel filter. Dont lose the little rubber o-ring! The material thats probably clogging your screen is actually little pieces of rubber that have rubbed off over the years from successive fuel filter changes........ i'm trying to remember when i had my psd..... i think i cleaned the bowl, then blasted the screen (mildly) with compressed air.

 

Goldenears, I will check that screen, I don't remember looking down in the canister when I changed the filter.

But, I think I can eliminate anything after the filter housing, as I used that shrader valve to check lp pressures? Or am I not thinking logically? Is there a screen of some sort in the tanks, It just seems odd that both tanks do the same thing


Rick

 

If you're seeing good pressure at the filter housing, maybe there is a restriction further down the fuel supply.
Something toward the injectors would still allow you to see good pressure on the supply side, but be cutting off fuel further down the line.

 

Well, normally I check fuel pressure first, There are no seperate fuel pumps in the tanks, it is one pressure pump, and I beleive this is the culprit

Thanks for the replies

Rick