Strange fuel problem

[jbarron]

I've got a strange problem maybe somebody else has ran into. After I shut my engine off it pushes fuel out the venturis and even out around the shafts.
This is on a q-jet and it does the same with a edelbrock 1406. Seems like I'm getting really high fuel pressure but its not running when this happens. Runs fine other wise. I'm not sure if the fuel pressure is suppose to drop after you shut the engine off. I'm thinking it might be a bad fuel pump or maybe a clogged vent line.

This is on a 72 with a 350.

[Wrenchbender Ret]

If it was just one carb a guy would say it,s the needle & seat or float. Being it does it on two different carbs the first thing to do is check the fuel pressure. If the pump is not bad you could put a fuel pressure regulator in line.

[76bonanza]

It could be Percolating from heat after engine is off can be a common problem try a phenolic or wood spaceer and see if that helps.

[jbarron]

Think I found the problem. Atleast it hasn't been acting up anymore. The return line fuel switch for the second tank wasn't working so it was basically clogged. This was causing it to over pressure the carb. Bypassed the fuel switch to only use the cab tank.