tboltkc

Has anyone ever had an FPR (mine is a Holley 1-15 I think) fail when it's hot and stop regulatiing fuel pressure?

Earlier tonight I had a lot of problems after driving for awhile and doing some in town driving. It would die at idle, and when I finally got back on the highway, it would backfire like a gunshot under full throttle. Got to where I was going, opened the hood and had fuel coming out of places that fuel shouldn't be coming out of, and the fuel pressure was around 6, which is too much for my Weber 45 DCOE. I had it set closer to 4 PSI. Drove home just now (much cooler outside) and checked when I got home and it was closer to 4 PSI where it should be. Could the FPR be going bad when it gets hot?

Thanks.

Paradox

iTrader: (1)

where is fuel coming out of? the FPR?

tboltkc

No, the fuel is coming out of the carb. It's dripping from the cover where the cam for the accelerator pump is - which I didn't think even had fuel in it. And I can smell fuel while driving when it gets hot too. My theory is that the FPR stops regulating and floods the carb.

BTW - I realized after I posted the first one that my gauge goes to 10 or so, but I'm not sure what the FPR's range is. I'm guessing it's the 4.5-9 one since I can't ever get my pressure below that. I need to try to find a 1-4 regulator.

trochoid

iTrader: (6)

If you have fuel dripping at the ap, replace the diaphram. When they go bad, they leak externally.

tboltkc

Does this apply to the Weber 45 DCOE or is this for a Nikki?

OnlyOnThurs

Is it difficult to replace the acc. pump. diaphram with the nikki still on the engine??? Or should that not even be considered as an option??

trochoid

iTrader: (6)

Nikki, and it's easier with the carb off. On the car is a chore, Sterling may mention an easier way in his writeups, don't recall for sure.

As far as the Weber, the ap diaphram may have blown from over pressure.

tboltkc

I just put on the Holley 1-4 PSI regulator so we'll see what happens. It was still set where I left it after my test drive.

Problem is now I lost my bypass/return line (I had a Mallory regulator), so I just blocked off the return line - is that ok or am I asking for trouble?

trochoid

iTrader: (6)

Holleys fprs are non-return. Mallorys are rebuildable and a better regulator.

Rx7carl

Yea your fine, just leave the return blocked.

Changing the ap diaphragm on the car is doable (Nikki). Just dont lose the circlip. pop the circlip, remove the 3 screws you can reach, slide out the pivot axle, then remove the last screw and the cover comes off. Easier on the bench but possible on the car.

tboltkc

I'll probably try to rebuild my mallory then, I don't like not having a return, I know it's hard on the pump.