Getting 97psi fuel pressure ... help

[Kegworth]

Was also thinking - while im at it, couldn’t i just bypass the selector valve all together and run in/out of main tank?

 

[alwaysFlOoReD]

Yes, you can bypass the selector.

 

[Kegworth]

OK update; I just disconnected the fuel return off of the regulator and ran a hose into an empty gas can, pressure key on engine off was 35 psi, then when I turn the engine on it was hovering around that boat fuel was pouring into the cans so fast I had to turn the car off. Is it normal for the amount of fuel to be returned? But, clearly there is a serious blockage happening on the return side so I’m going to go ahead and get underneath and try to reroute the hoses! But was very pleased to see healthy fuel pressure. Engine still sounded rough though, but I will conquer that next.

 

[RonD]

Good work sorting this out

Yes, if pump is capable of 90psi then 50psi will be sent to return hose and back to tank, at idle

One reason Ford changed to "returnless" and the higher pressure, 55-65psi, was to keep fuel in the tank cooler, so less vapor
"Returnless" is not really returnless, lol, it just has the return at fuel filter so fuel doesn't get as warm from circulating all the way to engine bay and then back

 

[Kegworth]

2nd update!!!! Big news. Turns out the stupid harness going to the fuel selector valve had a broken tab on it and had somehow unplugged itself!!! Which explain not only the blockage, but also my fuel gauge not working. Everything is working now and i didn’t have to do alllll the stuff i was about to do. Praiseeeeee!

fuel pressure holding at 30psi at 600rpm idle. And 33 ish with light revs. Pretty steady.
Hearing occasional pops, sounds metallic - like the motor jumps especially when revving... very intermittent, may just be the motor getting used to being able to pee again lol

gonna let it get up to operating temp then go for a drive and see how it drives.

 

[Kegworth]

Omg y’all. Biggest noob mistake of all time.... on return hose i left off.... gas went everywhere. Reattached it to filter (frame rail one) not sure why it does through that... but it’s still blocked after doing so. It wasn’t the tank selector valve. Looks to be either a line past the tank or that filter maybe. Gosh i feel dumb, def just killed a bunch of grass.

see image... isn’t that a filter? It’s before the selector valve, first stop on return line journey from engine.

 

[RonD]

Yes, thats the canister fuel filter, seen in previous post: https://cimg6.ibsrv.net/gimg/www.ra..._8350b2f018774c26bb244229ac6cf4c4ef1cb739.jpg

 

[alwaysFlOoReD]

Not necessarily a filter. They are used as a small reservoir for high engine loads. And can be both a reservoir and filter.

 

[Kegworth]

SOLVED:

After testing every before this / after this possibility to see where the blockage was. Which was a huge PITA... turns out it wasn’t the canister, and was literally the “through”return on the tank selector... which is apparently a valve. So before ordering a new one i decided to take a sharp pick and just stab inside of the inlet to the tank..... didn’t know what i was feeling but i got a little rough w it and sure enough fuel is-a-flowin!!!!

Everything is back together and idle is smooth as it’s ever been and fuel pressure steady at 29psi. Which i feel like it should be higher? (Thoughts?) but for now I’m content as can be because i know i can go drive down the road w out issues. Geez.
If it gives me issues again, I’m just gonna bypass the valve entirely. But for now all is well.

keyword: for now haha

 

[RonD]

25-35psi should be fine, as long as its consistent, computer will adjust fuel trims accordingly