VT Monte Posted February 15, 2021 Share Posted February 15, 2021 I have a brand new Brawler 750cfm carb installed on top of a ZZ383 crate motor and I think it's pretty much set up with proper float levels. I'm having bad flooding issues now though with fuel squirting out the overflow tubes and wet spark plugs. I actually had this issue with the old 4150 carb the Brawler replaced. When I can get the car to idle the fuel pressure gauge dances all over from 5psi up to 8+. I'm thinking it's the mechanical fuel pump so I pull that and it's a AC Delco or similar 3 port style with the return to the tank. Since I'm already plumbed with that return but don't want to just put another cheap pump on there I'd like to replace it with a performance 2 port pump and then install a fuel pressure regulator with a return to make sure I'm not exceeding the 6psi that Holley carbs are happiest at. Is there are major problem with what I'm proposing? I think I can just do tank -> pump -> filter -> regulator -> one outlet to the fuel rail the other to the return. In my head it's a six one way, half dozen the other compared to what I have now but with the extra insurance of the regulator. Quote Link to comment Share on other sites More sharing options...
MC1of80 Posted February 15, 2021 Share Posted February 15, 2021 Fuel coming out of the breathers on the float bowls indicates the floats are too high. I constantly run all my holley carbs at 8psi. Never had a problem in over 35years. That being said, if you want a good mechanical pump try the holley pump. Holley lists a few for the small block. Read the description and pick the one that best fits your application. I have the 170gph Holley pump on my 496. The highest fuel pressure mechanical pump that can be used without a regulator. I was going for a stockish look. Couldn't be happier with the pump. I would go over the float level adjustments again. With the car running, fuel pressure will fluctuate alot with a mechanical pump. Quote Link to comment Share on other sites More sharing options...
VT Monte Posted February 15, 2021 Author Share Posted February 15, 2021 If I have the return line already there I'm unsure what to do about it if I go to a 2 port pump without a return on it. Despite my searching, I haven't seen any Holley pumps with a return on them. Maybe I'll keep looking. Even getting the car to start and run is getting tough. Even with the floats set to lower the level as much as I can I still get spurts of gas out of the overflow tubes. Quote Link to comment Share on other sites More sharing options...
MC1of80 Posted February 15, 2021 Share Posted February 15, 2021 Leave. The return line off or cap it. Fuel still coming out of the vents even with the floats adjusted low sounds like the needle and seats are stuck or have debris in them. I would remove them end either check or replace them. Quote Link to comment Share on other sites More sharing options...
VT Monte Posted February 15, 2021 Author Share Posted February 15, 2021 I haven't pulled the needles. I assumed being brand new they'd be clean but I'll add it to the list to check. Thanks for your help. 1 Quote Link to comment Share on other sites More sharing options...
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