Fuel leak @ AFPR

[63tuner]

I am using SARD fuel regulator, yesterday i found out that the regulator leaked fuel at the top of adjustment screw and the pressure gauge. i used teflon tape but the regulator still leaks fuel. is there any other way to stop the leak?

 

[steve]

Sounds like the diaphragm is damaged. You'll have to repair or replace the regulator.
Fuel shouldn't be able to reach the adjustment screw.

 

[63tuner]

thanks for replying. i am sorry for the false information ,it is not leaking fuel on the adjustment screw, it only leak fuel at the pressure gauge and vacuum leak at adjustment screw. after putting some teflon tape the gauge still drops pressure after a few miles of driving .Even if i set it high at 42 psi, it will drop to 35 psi and the gauge's needle looks shaky. i checked the injectors, fuel pump, adjust the timing, checked for boost leak and nothing change.

 

[steve]

You should be able to seal the threads of the gauge using something like http://www.permatex.com/products/Au..._Permatex_High_Temperature_Thread_Sealant.htm

Keep in mind that non-fluid filled gauges can flutter as the pulses from the pump cause small changes in the pressure and that fluid filled gauges can be effected by underhood temp changes that cause the indicated pressure to drop as the gauge body pressurizes from the expanding fluid. Double check the gauge before spending too much time trying to figure out why it's changing.

If the tape won't seal the adjustment screw, you can try a o-ring under a nut to lock and seal the adjuster.

 

[63tuner]

ok, thanks again, is this happen to fluid gauges too? the purpose of me, trying to figure out why the fuel pressure drop was because my car seems to hesitate when moving.

 

[steve]

That's a good reason to suspect the FPR and you have found some issues that need addressing but I wanted to let you know that the gauge can be suspect too.

You can static check the regulator by turning on the fuel pump and then applying pressure and vacuum to the reference port nipple. The fuel pressure should track the reference port 1:1.

 

[tsitalon03]

Yea I had the same exact problem on my weapon-r afpr yesterday. I put 2 o-rings I bought from homedepot and put it around the threads of the fuel pressure gauge and screwed it back on. It helps alot but still leaks a tiny bit.....I'll be replacing that pos weapon r soon anyway .

 

[63tuner]

how do i know if the fuel pressure track the reference port 1:1?

 

[steve]

Apply 10 psi of pressure to the nipple and the fuel pressure should go up 10 psi.
Apply 20 in hg vacuum to the nipple and the fuel pressure should go down about 10 psi.

fuel pressure (psi) = base pressure (psi) + reference pressure (psi)

 

[63tuner]

ok ill try figure the way to do that pressure test.
,

 

[63tuner]

how do i apply 10 psi pressure to the nipple?blow through the nipple?