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Fuel Regulation

hefavitzen

Scrambler Junkie
BENEFACTOR
Gold Member
Lifetime Member
City
Rock Hill
State
SC
Hey guys, just an interesting item for you. I have a Chevy 383 with a mild cam and heads and have been running a Holley 750 4160 duel feed. I have been smelling gas since I installed the carb after the reman'ed Quadrajet I had been running bit the dust (butterfly rod had hollowed out the base plate!). So I finally got some help in tuning it (my 10 year old son came to help) and while I was turning it over to get some gas into the fuel bowls he start shouting that fuel was going everywhere.

What happened was when I shut the engine off the fuel was shooting up and out of the vent tube. I had been running my air cleaner lid upside down due to hood clearance issues and I had noticed that there was a fluid stain on the lid radiating from the hold down rod and nut. I had a fuel pressure gauge I'd never put on so I put it on and sure enough, my mechanical fuel pump is pushing 10.5 PSI constantly. Holley recommends 6.5 and 7 PSI tops. I think the fuel pump is pushing so much fuel into the bowls its shooting out the vent when I turn the engine off just to relieve the over-pressure and that is why I smell gas all the time when I park it.

Due to the duel feed carb I had to order a set of duel feed hoses for the regulator. I am running some braded stuff so I figured I'd keep the theme going. I'll let you know if/how it helps once I get the fuel pressure dialed back!

Jeff
 

John N

Addicted....Ex-SOA VP
BENEFACTOR
Gold Member
Lifetime Member
SOA Member
City
Rockville
State
VA
Something that may help a bit. Run a rubber line from one vent to the other, with a couple of v-notches cut into the top of the line. It’ll cut down on any slosh over and help contain the excess.
 
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