Ok so over the summer I swapped my 305 TBI for a 350 Carb motor. Im still working the bugs out.

Last night I was doing test runs and after about a half hour I noticed bogging and eventually complete motor power loss. After that it was very hard to get it started. It did not over heat and I believe it is a lack of fuel issue. When I did the swap I just cut the wires on the stockk pump in the tank. So the mechanical pump has to suck fuel through that and into the carb. Do you think this is too much for the pump? Like it would be getting stressed? Because it started right up today no promblem.

 

My buddy has an 86 GM pickup that he did the same thing to and it pulled fuel through the old pump no problem.If you have to I've herd all you have to do is drop the tank and take out the pump and extend the pickup tube. Usually you put a screen type filter on the end of the tube aswell.

 

Why not just use a Mallory 4309 pressure regulator and reconnect the electric pump?

An external electric pump will die trying to suck fuel through a non-operating in-tank pump, can't imagine a mechanical pump doing it well.

Also, did you remove the evap canister and vent the fuel tank? When I swapped to carb, I removed evap canister and ran the 3rd fuel line (vent line to the evap canister) out through the underside of the car, so there wasn't any pressure buldup in the tank.

 

Does that allow a good bit of your fuel to evaporate in the summer? I'm doing a swap similar to this and the most confusing thing is working out the fuel issues.

 

If your going to reuse the electric pump make sure that if it has a return line the regulator you get has a return on it aswell. It's not a good idea to deadhead a pump. I went through 2 pumps on my pickup before i smartened up.

 

I have no fuel evaporation.

Not sure where folks get the idea that fuel evaporates so quickly - put a 1/2 gallon of gas in the gas can for the lawn mower, leave the vent open, and set it behind the shed - mark the side of the can - leave it for a year, and see where the level is - practically the same as a year ago.

If your not going to drive the car, you need to put in stabilizer like Sta-Bil so it doesn't turn to varnish, but the evap process is very very slow. Evaporating fuel is an excuse for those that were too drunk to remember that last drive but don't want to admit it!

 

Ok. I put a new fuel pump on and an in-line fuel filter. I changed the oil and filter. After all that it wouldnt even start up. Here there was dirt in the needle and float. Got that taken care of and hook up the electric choke. It runs absolutely amazing. Almost like its fuel injected. The only thing I have left to do is hook up the reverse lights.

In order for this 350 to run like a clock I only need a few more things.
-Drop tank get rid of fuel pump and wire gas gauge.
-Get a square bore intake where adaptor is not required (mine has a vaccum leak)
-Get some high quality header gaskets
-Dress the engine up


Ill Try and get some pictures up tonight for those who care.

Whoever is planning on doing a EFI to Carb swap I wish you good luck. Its been a great learning experience. Im only 17.