Fuel pressure psi

[classicpw]

I'm about to check my fuel pressure but I have no idea what it should be. Let's say that it comes in too low... fuel pump?

[pipelayerjdh]

I've read you need a minimim of 40 psi.

[Diesel_Diagnostician]

What year of truck is it? Untill 1998.5 the pump was a two stage pump raising fuel pressure from 4 psi (from the tank) to 40 psi to fill the injectors...if its a 1998.5 and up then the pump is electrically operated and pressure should be 51 psi +/- 4 psi....i like to check the pressure on the heads and then on the outlet of the electric fuel pump...(driverside behind cab) just to see how much restriction their is in the system...

[classicpw]

1997, OK I'm lost. Went to the auto parts store and the fuel pressure tester didn't come close to fitting, what are you guys using to test

[klpaul]

I just took an old fuel filter top and tapped it with a schrader valve. Anytime I need to test pressure I just put it on and then test. Especially helpful on the ones without spots on the heads and frankly easier anyway. Just an idea.

[djsdiesel]

on a 97 there is a schrader valve on the back side of fuel filter housing. on 99+ you either have to get some fittings and install a schrader valve on the filter housing or do like klpaul and I have done a put a schrader valve in a filter lid and install it when you need to check pressure.

[Tx_Atty]

the 97 will be around 55psi but International recommends up to 70. I plan to shim mine to 65 when I get the chance.

If you just press a gauge against the schrader you are going to spew fuel everywhere. I replaced mine with a fitting that will do one of two things (your option) - fit directly to a gauge, or, attach a fuel line to put the gauge elsewhere. Currently I have a fuel line going to a pressure isolator that then shoots a line into my cab. It is plugged at the moment but I am buying a glycerin filled gauge (to absorb the pulses from the mechanical pump) next week so i can monitor pressure at idle and on the road.

for reference, do not use a dry mechanical gauge. THe needle flutter from the mechanical pump will make the gauge completely illegible. You need a glycerine filled gauge no matter how you set it all up.

[classicpw]

Thanks for the responses guys. What is the valve that looks like tire pressure fitting complete with cap on the front right of the filter? I'm ready to just replace the fuel pump. The truck has 120K on it and the pump is all corroded and nasty looking. It has to need a new one soon. I spoke to an area Ford mechanic and he seems to think that's the problem. He claims that they go up every 100k. I just don't get it. The truck runs great, fires up like it's new, it just starts to die after around 10 minutes of driving, it'll drive fine at 5-10 mph, but if i press the gas too hard it starts to flutter and sputter, but has not died.

[djsdiesel]

thats where you check the fuel pressure, have you tried replaceing the fuel filter. I just replaced one about two weaks ago that had 175k on the original pump. And it was replaced because it was leaking not because it wasnt making fuel pressure.

[classicpw]

Just replaced it last week.