- Joined
- Aug 8, 2018
- Messages
- 376
- Reaction score
- 194
- Location
- California
- My Car
- 72 Fastback - 351C-4V, Fitech EFI, T56 Magnum 6 Speed
Hello, picked up a 72 Fastback with a 351C 4V a few months back. Been working my way through an auto to 6 speed manual trans swap and am now struggling a bit to get the engine running right. The car starts and runs well once it warms up, but at low RPM it just falls flat. Once RPM gets a bit higher, its great and pulls hard, but off the line it's terrible to the point of being difficult to drive as it will sputter miss.
It's running an Edelbrock intake and 1407 750 CFM carb with a Mallory HyFire 6A ignition and long tube headers. Went through the fuel system, new plugs, wires, coil, tried timing all over etc. It's all way better now than when I started working on it, but still has that dead spot that makes it a handful to drive. Accelerator pump seems to be working OK and changing to the position on the pump linkage doesn't seem to make a ton of difference.
I don't have a lot of info on the engine. I was told it had a mild cam, but that was unclear as the previous actual owner was not available and the info was maybe 3rd hand.
From the beginning it seemed like this might be too much carb for the car but I really don't know enough about this engine or the 351C to know if that's true or if that's what is causing this issue. I'm not in a position to just buy another carb to see if that might work right now, so hoping I can get this sorted out enough to make it more drive-able.
Thanks for any advice.
It's running an Edelbrock intake and 1407 750 CFM carb with a Mallory HyFire 6A ignition and long tube headers. Went through the fuel system, new plugs, wires, coil, tried timing all over etc. It's all way better now than when I started working on it, but still has that dead spot that makes it a handful to drive. Accelerator pump seems to be working OK and changing to the position on the pump linkage doesn't seem to make a ton of difference.
I don't have a lot of info on the engine. I was told it had a mild cam, but that was unclear as the previous actual owner was not available and the info was maybe 3rd hand.
From the beginning it seemed like this might be too much carb for the car but I really don't know enough about this engine or the 351C to know if that's true or if that's what is causing this issue. I'm not in a position to just buy another carb to see if that might work right now, so hoping I can get this sorted out enough to make it more drive-able.
Thanks for any advice.