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Chrysler 4418850 - 5277829 - 5277864 FPRs

Posted: February 7th, 2016, 12:17 pm
by Comanche91
My Hesco AFPR won't adjust anymore - it's fixed now at 40 psi w/ vacuum hooked up and won't go any higher. I had been running it at 49-50 psi for years with the Hesco regulator with good results. My injectors are the Mopar 53030778 gray tops that run at ~49psi. I have read on GoJeep's site and many others that the Chrysler 4418850 or 5277829 or 5277864 fixed regulators work fine on a 4.6 stroker and are PnP on the fuel rail. Rather than spring for a new Hesco adjustable FPR, I'd like to try one of the Mopar fixed regulators. Is anyone using one of these regulators on their rig and how do they perform? This looks like it might be a good alternative, and a bit cheaper too..........

Re: Chrysler 4418850 - 5277829 - 5277864 FPRs

Posted: February 7th, 2016, 4:20 pm
by gradon
So it won't adjust period? I'd put a new fuel filter on and double check fuel pump ground and harness pins/connection. Does it run worse(since you have a custom tune based on higher psi)?

Re: Chrysler 4418850 - 5277829 - 5277864 FPRs

Posted: February 7th, 2016, 4:41 pm
by Comanche91
Yes, the FPR will not adjust any higher than 42psi. The last time I checked it I had it set at 48psi w. vacuum hooked up. So it's something internal in the regulator I think. It seems to be running fine. I verified that pressure gauge is okay with another - same reading. The pump is a fairly new Bosch and the filter is recent too.

Re: Chrysler 4418850 - 5277829 - 5277864 FPRs

Posted: February 7th, 2016, 6:29 pm
by Comanche91
Disregard all I wrote about adjusting my Hesco FPR. I had forgotten that the 49psi reading I was trying to reach is with NO VACUUM LINE ATTACHED. :doh: It has been awhile since I last adjusted it. What an idiot.........

Re: Chrysler 4418850 - 5277829 - 5277864 FPRs

Posted: February 7th, 2016, 7:18 pm
by gradon
;)