walkerjt

I swapped '86 2.8 V6 for an old 350. I took out the old in tank pump and added a mechanical pump on the block. It has a 4bbl carb. It runs great for 5 min then starves for fuel and dies. Any ideas appreciated.

topless87

What are you using as a fuel pickup in the tank now? Didn't the old pump have a "sock" on the bottom which picks up fuel? I have used a piece of fuel line so that it goes completely to the bottom of the tank in my son's and run a pre-fuel pump fuel filter in case it picks up any junk since it no longer has a "sock" filter on it.

walkerjt

It did but I replaced it with a stainless steel screen. The tank was cleaned and sealed years ago. I wonder if the sealer has failed and is clogging the screen. Maybe the 5 minutes it runs good is just until the screen clogs again after sitting. I sure don't want to drop the tank again. What about cutting an access hole?
Thanks for your reply.

topless87

Used compressed air and blow back thru the supply line as a test before you go to all that trouble. You will be testing to see if it makes any difference when you try to start and drive the car again. If it makes a difference then you know where your problem could be. Have you tried an electric pump? That is also a test for fuel flow and you dont have to start the car if you use an inline pump and a catch container as you look at the flow volume.

RedLeader289

iTrader: (2)

I had the same problem when we first dropped the crate engine in mine. Used a mechanical pump on the block, it'd run for a few minutes, then sputter and die. Swapped the mechanical pump for an electric inline pump (by the tank) and all the issues went away. I'm 99% sure your fuel is getting too hot and boiling after a few minutes.

Try an inline electric pump or a new electric pump in the tank, should solve your issues.

Gibbyzracing

sounds to me like a vapor lock issue. When it does it stop and see if the fuel line from pump to carb is hot.

midias

Are you using a venting gas cap? Try running without one and see what happens.