fuel pressure changing

[dan2288]

yeasterday ot was at 34 psi, right were it should be. Today I was looking at the guage and it was at 40 psi and the needle was moving all around. What could be wrong ?

 

[c4uldr0n]

yeasterday ot was at 34 psi, right were it should be. Today I was looking at the guage and it was at 40 psi and the needle was moving all around. What could be wrong ?

Things to check:

1. Odd voltage to fuel pump
2. fuel pump going bad? (maybe)
3. Leak at fuel pump (in tank, bad o-ring)
4. Fuel pressure regulator diaphram going bad
5. bad gauge
6. leaky vacuum source

Thanks,

c4

 

[snowborder714]

What type of gauge are you using (liquid filled?) and where is it (on AFPR, in cabin, etc.)? If it's on the AFPR, did you put teflon tape on the threads of it before installing it? It could be leaking.

Where do you have the other end of your vacuum line connected to (the one that's on the AFPR)?

Also look into the above suggestions.

 

[dan2288]

yea, its a liquid filled guage. The vacuum line is connected to the intake maniflod.

 

[Nvisabl]

yea, its a liquid filled guage. The vacuum line is connected to the intake maniflod.

Assuming you are checking it with the vacuum hose attached (which is not the way I would check it), was the idle different had the barometric pressure changed significantly. These things would change fuel pressure at idle unhook vacuum line and see if it varies from day to day that is the more important item.

DJ