Fire time!!!!!!!!!!!!!

[Sinister Chevy]

This one is driving me nuts! I just replaced my old edelbrock carb with a new one because it was leaking from the '? lower air valve shaft?' (Not sure what to call it but it exits the carb at the rear left.) Now the new one is doing the same. it seems only to happen when the air pressure builds in the tank (even when it has been sitting). Whats the deal? Is a vented gas cap going to cure this? Or is my fuel pressure to high? P.S - I also recently replaced the fuel line and filter.

[long69]

i had one do the same thing(maybe).i could get no answers so i switched to a holley. its to bad because it really drove and ran nice. but since then i have heard that high fuel pressure might cause this. i never checked mine to see.

[Shyguy]

You definately want to make sure your tank is vented. If it is not vented your engine can draw a vacuum on it and cause fuel flow problems. If pressure is building up in it when it sets that could be bad for the carb.

I have heard from posts on here that Edelbrock carbs like a constant pressure to work right, of course I don't know personally because I have always had Q-jets.

[storm9c1]

Originally Posted by Shyguy

You definately want to make sure your tank is vented. If it is not vented your engine can draw a vacuum on it and cause fuel flow problems. If pressure is building up in it when it sets that could be bad for the carb.

I have heard from posts on here that Edelbrock carbs like a constant pressure to work right, of course I don't know personally because I have always had Q-jets.

+1

Yes, Edelbrock carbs need volume but not pressure. They start acting up if pressure deviates much from 6psi. They are especially sensitive to high pressure, very similar to some older Carters. Your best bet is to replace your fuel pump with an Edelbrock pump that needs no external regulator (works great and solved my problems before). Or install a regulator and set it no higher than 6.5psi.

[cdowns]

there should never b a pressure buildup in these gas tanks, the tank needs a working vent system. lots of edelbrocks have problems caused by not using a nonmetalic phenolic spacer between carb and manifold

[Clyde65]

have you recently replaced the fuel pump? I had the exact problem on a few Q-jets, when I finally pulled my head out I checked the fuel pressure and found out I put a high volume fuel pump on it that was putting out like 15 PSI, switched that out and all was good.

[Bpokey]

Originally Posted by cdowns

there should never b a pressure buildup in these gas tanks, the tank needs a working vent system. lots of edelbrocks have problems caused by not using a nonmetalic phenolic spacer between carb and manifold

I agree. I had the same problem with a Edelbrock I had a while ago and it would boil the fuel out of the bowls. I have run a Holley for over a year now with no problems.