I am working on my '85 Capri RS fuel system. Can anybody tell me how much fuel pressure a 4180 likes to see? I am running an 80 gph Holley mechanical pump. Holley says it doesn't need a regulator but I have a feeling I am going to need one.
I am working on my '85 Capri RS fuel system. Can anybody tell me how much fuel pressure a 4180 likes to see? I am running an 80 gph Holley mechanical pump. Holley says it doesn't need a regulator but I have a feeling I am going to need one.
6 or 7 psi is enough.
1985 GT, Sunroof, 5 Lug, Rear Discs, 01 Graphite Bullets, 88 forged piston shortblock, 2.02/1.60 Alum heads, Weiand Stealth, Holley C950 TBI, BBK Long tubes
Yeah I was thinking maybe the new fuel pump was putting out too much pressure. I need to make up a gauge and see where it is at.
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Is the fuel return line off the pump back to the tank in working condition?
HAD
'82 GT monochromatic (red)...black cloth
HAVE
'85 GT vert two tone (white on charcoal)...white leather
'00 F350 two tone (white on silver)...gray cloth
'00 Excursion Limited two tone (white on tan)...tan leather...wifes ride
'08 Taurus Limited ice blue...tan leather...daughter ride
'08 Edge Limited white sand tri-coat metallic...tan leather...other daughters ride
Well with the Holley pump it doesn’t have a return provision. A little back story on the set up. I pulled the motor and put on a different set of heads and cam. I switched the factory fuel pump to the Holley 80gph pump and now the car won’t idle and is fouling out the plugs. I have a 600 double pumper That will be going on, I just put the stock carb back on to get it fired up and running.
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Last edited by Adriver; 09-27-2018 at 03:59 PM.
5-6psi... or lower, and bigger needles and seats for adequate fuel delivery without frothing in the bowls from excessive pressure, is best. The quick and easy way to tell if you have excessive fuel pressure is to look at the float/fuel levels in the float bowls after the pump change. If they were previously correct and now they are higher, because the floats need to exert more pressure upward to shut off the incoming fuel... there's your issue. Does the car have or still have a return provision, a return line to the tank? Find out what the as is dead-heading pressure of the way it is now is, and if it's too much, make your own damn return between the pump and carburetor with a T with a sized restriction (1/16", 1/32", etc) inside it, connected to your return line... see my build thread for how I made one for with a low pressure in-tank electric fuel pump to get the fuel pressure exactly where needed.
Last edited by Walking-Tall; 09-27-2018 at 05:06 PM.
Mike
1986 Mustang convertible ---> BUILD THREAD
Past Fox-chassis "four eyes":
1983 Mercury Cougar LS
1986 Ford Thunderbird ELAN
1980 Capri RS Turbo
Work in progress website ---> http://carb-rebuilds-plus.boards.net/
Cool, I’ll check that out. Thanks.
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5-6 psi is plenty
Hooked the regulator last night. After messing with the car I finally got it to idle. Still isn’t even close to being right, but it is a start. For some reason the regulator doesn’t want to let me adjust the fuel pressure much. I had it at 5 now I can’t get it to adjust back up to 5. Kinda has me thinking the regulator is junk, which would be just my luck
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