90rocz

I'm getting a '64 Impy SS road ready, after noticing fuel contaminated oil, I replaced fuel pump.. Now when I try to start the car it shoots fuel out of the bowl vent like a fountain!
I checked the fuel pressure and it pegged my 10psi V Vac/Fuel combo gage...
Can a $13 replacement pump put out this much fuel??I mean this thing could feed a hungry BBC...
Could the problem be somewhere else, seeing how this could easily account for the fuel soaked oil????
Anyone experienced this??
Thanx...!
Oh, I replaced the needle and seat, no change!

BamaZ28

If the pump wasn't set to stop at 8psi, heck yeah you would have problems

spinout

sounds like the float is stuck open

BamaZ28

flloat in the carb? would that make his pressure go sky high?

spinout

pressure should be about 15psi normally so if the float was stuck in the bottom of the bowl fuel would shoot out everywhere

BamaZ28

hmmm, when I bought my carter mech fuel pump, it is set at 8psi, I though 15 was too much

MikeRock

yeah your float is deffinatly stuck, i had the exact same problem with the 750, if you know how to fix it go for it, but if not take it to the shop shouldn't take more than an hour.

AutoRoc

You are getting way too much pressure. I seen this scenario 3 times this year. Once with myself when I tried running 8.5-9PSI to help rich a nitrous tune. Backed it down to 6PSi and it was magically fine again. 3 Port mallory Fuel pressure regulator saved me.

My dad also seen the same problem...Terrible idle, fouled plugs, etc...His cheapo mechaical fuel pump was pushing exactly 10PSI...A mallory 2 port regulator fixed that just fine taking it back down to 6 PSI...I can go on if you'd like...

spinout

u shouldent need a fuel pressure regulator on a mechanical fuel pump u should be able to bolt on a fuel pump and drive it i build cars for a living
don't play with pumps just put a factory pump on it a be done with it and fix the floats

texlurch

2 things cause fuel to shoot out of the bowl vent

float hanging or sticking

too much fuel pressure


most stock carbs can't handle much over 6-7 psi at the bowl, so you may need to add a regulator...

spinout

what do you have on it for a carb first off the engine had a stock pump on it from factory and didnt need a pressure regulator so i would assume that you have a carb problem or your return line from the pump to the tank is plugged thus the high fuel pressure so blow back through the return line if its not plugged its your carb

90rocz

Thanx, it WAS the factory replacement fuel pump, "Master" brand. I took it back and got another one, problem solved. thanx