Super Duty FPR mod?

[tneibling]

Is it possible to shim the fpr spring in a superduty like you can do in an OBS? I have been searching around but haven't found much.

[enoyes12]

Did you do a search for FPR mod? What year super duty?

[GONEFISHINTODAY]

In the FPR there is a spring. I've heard of people putting a small bb in line with the spring to increase the spring rate. Best to get another regulator that you can dial up the pressure you want.

[tneibling]

Yeah i searched for "super duty fpr mod" just to see if was possible with a SD. I did the FPR mod to my old 97 and was wondering if it was something that you could also do to a SD.
My SD is a late 99. I figured that with 270k miles the spring is probably getting a little tired.

[Highwaywrench]

yes, you can do it, it is a pain in the butt, yet do-able. I used a small metric screw that fit into the housing part, to shim the FPR. however, like mentioned earlier, it would be better to get an adjustable regulator in order to accomplish your goals

[tneibling]

Alrighty thanks for the info guys.

[tubular031]

I would not mess with it. if you crack the housing it costs more then its worth to fix. I run about 55 to 60 on the diesel side and 70 on the VO side. I feel NO difference empty or grossing 22k on either pump. I also will drop to about 45 to 50 grossing 22k on diesel and still feel no change when pushing a solid 70 psi on the VO side pulling the same load.

[powerhoghp]

You mean something like this....? GDS Fuel Spring

[choupique108]

or just do a regulated return and up the fuel pressure and help the injectors out.

[tneibling]

Originally Posted by powerhoghp

You mean something like this....? GDS Fuel Spring

Yea something like this was what I was thinking about. The main reason was since my truck has 270k miles I figured the stock spring was probably getting a little weak.

If I had the funds, I would do regulated return in a heartbeat, but living expenses and college must come first.

Thanks for the advise guys!