Engine/Transmission (1998.5 - 2002) FASS pressure regulator

I just installed my new VP, and want to lower my FASS 150's fuel press from the 22psi its at right now. The new spring is on its way but I can't seem to remember which plug the spring is under on my FASS. I searched the forums and can't find the answer. Thanks for the help.

 

The spring is under the return port which is "t'ed" into the filler neck

 

The pressure relief valve is in the middle of the pump. See the attached photo. It goes in the round hole in the center.

 

Thanks for the correction,Dan. I wondered if I had that right. By the way, I'm getting 25-30+ psi with my 95 hpfp. I've got the weaker spring in too. What's the next thing to do to lower the pressure. I think , ideally it should run about 15 psi.

 

I'm not sure what you mean by "dead head" but about the gauge: it's a Westach electric unit. I was unsure & installed a second sending unit which reads just like the original one. Initially, I had a 16 psi unit on it but that just pegged at the top so I replaced it with the 30 psi unit. The pressure tap is at the injection pump.

 

Was the second gauge a mechanical unit or electric? AND if it was a different electric gauge, did you use a differant sending unit or leave the same one installed?



I have seen Westach gauges give some funky readings in the past... . mainly due to the sending unit being on top of the VP-44 inlet. This pump will beat thoes sending units to death. I had to even put a snubber inline on my mechanical gauge because it was buzzing soo bad.



With you being tapped at the VP..... that limits us from dead heading the line to the HPFP without moving the tap. [/QUOTE]



It was a second sending unit I used but with the same gauge. The tap is on the Schrader valve & is connected to the sending unit with a 2 ft rubber line.

 

I have my supply line installed with a JIC tee at the pump, I can pull it and dead head it with a plug installed. My FASS pump is a 150 SN# 6080, when I get home I'll dead head it and recheck. My pressure has been 22 - 23 psi since I installed it in December of 05 using an Isspro gauge.

 

I also have a fass 150-95 and it runs at 20-22 psi

 

I checked pressures and had 22 psi dead headed. So I took off the hose and fitting for the regulator and removed the spring. My new one hadn't come yet, so I took my torch and put just a bit of heat to the spring to de-tension it a tad. Re-installed it and now have a 16 psi spring.



Of course I'll install the new spring when it arrives. I have to go out of town and wanted to have the lower pressure for the new VP from the get go. As it is I'll probably lose sleep over driving the truck 2 miles testing the new VP and injectors before adjusting fuel pressure.



My pump must be a 150/95, I guess I'm pretty confused about the model numbers. I just know mine has the big ol' expensive Filter & FW Sep. hanging from it. Now I just will have to get used to seeing my FP gauge reading something other than 22 psi.



Thanks for the response on where the regulator spring is, and I hope for many more trouble free miles with your fine product!

 

Hi Dan, just installed a fuel pressure gauge and my new FASS 150/150 is running right at 14-15 PSI ... Perfect no?



Cheers, Bill

 

everybody talks pressure. vp44 pumps pulsation diaphram seem to get damaged with high pressure (over 15psi) it is control flow rate that is important, under full fuel demand there should be no negutive fuel boost pressures. regulated flow plus fuel pressure should be the norm. Is fass the correction to the problems. Fass looks impressive, I am looking to upgrade but want a system that does not overpressure but delivers the volume the vp44 requires so that it suction press do not see the less than 7 psi

 

My fuel pressure has been at 22psi since I installed my fass 110K ago. I now have 203K on the original VP44. If it is a problem it hasent effected me yet.

 

During a conversation I had with a well known VP44 rebuilder, he told me unless I race or sled pull to keep it under 20 because there is overstress put on the pump at higher pressures than that. Do what you want with that info. He convinced me to go to the recommended 13. 5 and have enough flow to keep it there under load.

 

Dan, thanks! I really like this setup... . I immediately noticed that my truck idles smoother as soon as it fires. Also, the noise is negligible and I cannot hear it with the truck at idle. I can't wait to get some miles on this. .



Cheers, Bill