fuel pressure question

[jasonc84]

So about a week ago i changed the fuel pressure gauge because the one my notch came with wasn't working anymore. So new gauge read 60psi at idle so i asked around and found out that my acufab FPR could be broken. So i picked up a stock FPR and installed it today, started the car up and the pressure went right back to 60psi. So now with 2 fprs and 2 gauges (first one use to work) i'm still at 60psi. Ive also heard maybe there could be a blockage somewhere, looking for any other problems i could look for and also how to fix a blockage problem if that is it.

 

[jrichker]

Mustangs use a shunt style regulator that bypasses the excess fuel back to the tank. If the return line is kinked or crimped, it will make the pressure increase.

 

[jasonc84]

ok so checking the return line seems like the easiest place to start thanks for the response. Also any other sugestions are welcome so i can have more than one thing to check tomorrow.

 

[jasonc84]

any other potential problems that could cause this??

 

[JChalfan]

I agree with jrichker about the kinked return line. I had that problem on one of my 5.0's after an engine swap. The rubber part of the return line got snagged on something and kinked, and my fuel pressure was way too high.

How's the car running/driving? I would think that it wouldn't run really great with the FP at 60psi. It should at least be running really rich.

Jeff

 

[jasonc84]

it is def running really rich, you can smell unburnt fuel and it wont pass emisions, the idle is pretty good though surges every now and then but its pretty steady, im a mustang noob so where is the return line, do i need to jack the car up to check it??

 

[JChalfan]

it is def running really rich, you can smell unburnt fuel and it wont pass emisions, the idle is pretty good though surges every now and then but its pretty steady, im a mustang noob so where is the return line, do i need to jack the car up to check it??

There should be two lines running from the fuel rails, one feed and one return. The return should be the smaller of the two. Steel lines run from the back of the car to the front, then there is a pretty short rubber section, and then metal lines again going into the fuel rail. The rubber section will be on the passenger side, just follow the metal lines from the fuel rail. You shouldn't have to jack it up to check it, I don't remember for sure how much you can see from the top.

Jeff

 

[Flavadave4]

I think those guys have the right idea, is it possible you are that far out of adjustment?

 

[jasonc84]

im not sure how it could be that far out of adjustment with a stock FPR in there and stock fuel pump, stock injerctors etc. The whole fuel system is stock so doesn't really make sense to me.

 

[Flavadave4]

im not sure how it could be that far out of adjustment with a stock FPR in there and stock fuel pump, stock injerctors etc. The whole fuel system is stock so doesn't really make sense to me.

Sounds like something is blocking the return line.

 

[jasonc84]

hopefully its just a kink somewhere so i don't have to replace the return line.