Hey,
I'm looking for some tips after rebuilding my holley double pumper. When I stomp on the pedal (idling) the car will sputter and if I press moderately it will spit fire out the primary and air out the secondary. If I press the gas gradually, there's no issues and it revs as expected. It does while driving but a bit less so. I set the pumps to "factory position" Where they're just about pressing gas through on. Basically, as soon as I blip the throttle, they squirt. The throttle cam is in position 1 with the white insert. The nozzles I believe are the stock ones, I tried putting larger but it just lit on fir in the primary (won't be going back to that shop anymore... idiots).
I do have two other issues:
- The fuel mixture screws won't affect the vacuum unless they're removed entirely.
- Idle RPM is high once warm. 600 cold and 1100 when warm. Warm or cold, in gear is 550.
- I've rebuild the carb with a holley trick kit.
- Installed new MSD cables
- Installed 2x silver (light) springs and red bushing on the MSD distributor
- Clean the contacts for the cables under the cap
- Checked for leaks by choking out the carb; It dies quickly when I cover the carb
- The vacuum sits at around -13-15
- Set the initial timing to 6° (stock)
- Redid the seal on the intake manifold when swapping to an edelbrock performer
- Fuel bowls are set to trickle a little gas out the sight holes if I rock the car good enough
- Throttle plate gap set to where the idle gas slot is squared
My setup:
1972 Mach 1
351c w/ 2v heads
Holley 4150 750 classic double pumper w/ electric choke (p/n: 0-4779CE)
MSD ignition kit: 6AL controller with MSD distributor, coil and cables
Banging my head up against the wall. What'd I miss?
I'm looking for some tips after rebuilding my holley double pumper. When I stomp on the pedal (idling) the car will sputter and if I press moderately it will spit fire out the primary and air out the secondary. If I press the gas gradually, there's no issues and it revs as expected. It does while driving but a bit less so. I set the pumps to "factory position" Where they're just about pressing gas through on. Basically, as soon as I blip the throttle, they squirt. The throttle cam is in position 1 with the white insert. The nozzles I believe are the stock ones, I tried putting larger but it just lit on fir in the primary (won't be going back to that shop anymore... idiots).
I do have two other issues:
- The fuel mixture screws won't affect the vacuum unless they're removed entirely.
- Idle RPM is high once warm. 600 cold and 1100 when warm. Warm or cold, in gear is 550.
- I've rebuild the carb with a holley trick kit.
- Installed new MSD cables
- Installed 2x silver (light) springs and red bushing on the MSD distributor
- Clean the contacts for the cables under the cap
- Checked for leaks by choking out the carb; It dies quickly when I cover the carb
- The vacuum sits at around -13-15
- Set the initial timing to 6° (stock)
- Redid the seal on the intake manifold when swapping to an edelbrock performer
- Fuel bowls are set to trickle a little gas out the sight holes if I rock the car good enough
- Throttle plate gap set to where the idle gas slot is squared
My setup:
1972 Mach 1
351c w/ 2v heads
Holley 4150 750 classic double pumper w/ electric choke (p/n: 0-4779CE)
MSD ignition kit: 6AL controller with MSD distributor, coil and cables
Banging my head up against the wall. What'd I miss?