Which fuel return is best?

[Johnathan S]

I have an edelbrock AVS2 and it has 2 fuel inlets on either side, one side is plugged so it is just the one for now but I have a clear fuel filter and after driving on hot days I can see the fuel boiling in it. Now there is no vapor lock and it does not seem to interrupt drivability too much. But on my mechanical fuel pump it has 3 fittings one from the tank and one for the carb of course but there is another one that runs to a factory return line. So i'm thinking of just putting a fitting on the other side of the carb and plumbing it to that factory return line. that way fuel is going through the whole system in one side of the carb out the other and back into the tank. Will this work better? is it a stupid idea? im curious and what some other opinions. I like doing test like these and figuring out what works and what doesn't

 

[Dutch Rutter]

I personally don't see that working out too well. The carb inlet will try pulling gas, not push gas. While the fuel pump will still be trying to push the return fuel so the carb will pull the fuel from the return side of the pump...

I could be wrong about this. But I'd leave it alone and instead add a plastic or wood carb spacer to cure any possible vapor lock issues. Are you also sure the fuel was boiling and not just bubbling like air being sucked in one of the lines?

 

[Johnathan S]

I personally don't see that working out too well. The carb inlet will try pulling gas, not push gas. While the fuel pump will still be trying to push the return fuel so the carb will pull the fuel from the return side of the pump...

I could be wrong about this. But I'd leave it alone and instead add a plastic or wood carb spacer to cure any possible vapor lock issues. Are you also sure the fuel was boiling and not just bubbling like air being sucked in one of the lines?

it only bubbles when its hot after driving, it doesn't do it if its cool outside im talkin on a hot day. and I do actually have one of those spacers your talkin about. but if I did run this set up id plug up the return fitting on the pump.

 

[C10MixMaster]

I have an edelbrock AVS2 and it has 2 fuel inlets on either side, one side is plugged so it is just the one for now but I have a clear fuel filter and after driving on hot days I can see the fuel boiling in it. Now there is no vapor lock and it does not seem to interrupt drivability too much. But on my mechanical fuel pump it has 3 fittings one from the tank and one for the carb of course but there is another one that runs to a factory return line. So i'm thinking of just putting a fitting on the other side of the carb and plumbing it to that factory return line. that way fuel is going through the whole system in one side of the carb out the other and back into the tank. Will this work better? is it a stupid idea? im curious and what some other opinions. I like doing test like these and figuring out what works and what doesn't

Does it bubble with the engine on or only after it is shut off? I would expect it to bubble with it off and no fuel pressure. If your worried about vapor lock that happens on the suction side of the pump not the pressure side. If you do run a return line from the carb make sure your pressure regulator is on the return side. I think this is one case where if it aint broke dont fix it. Probably better spending your time and money on other things

 

[Johnathan S]

Does it bubble with the engine on or only after it is shut off? I would expect it to bubble with it off and no fuel pressure. If your worried about vapor lock that happens on the suction side of the pump not the pressure side. If you do run a return line from the carb make sure your pressure regulator is on the return side. I think this is one case where if it aint broke dont fix it. Probably better spending your time and money on other things

Yeah probably right, I think it might be only after the truck is shut off so that would make sense