I have a 1966 Mustang with an Autolite 1100. I sent the carb and had it rebuilt by a reputable company in Washington state. No real issues before the rebuild except a "flat spot" I'd sometimes notice when accelerating and it was very stained. The carb came back looking great as expected. I installed the carb and at the same time changed plugs (gapped to .034) plug wires, dist. cap and rotor, and oil/filter (as the car had been siting in the garage for a few months.) The car started fine, and idled well - I then noticed the fuel pump was leaking, so I shut the car off (before it warmed up) and replaced the pump as well. Restarted the car and idles great cold and warm.
My problem is:
When I quickly open the throttle from idle when the engine is warm and choke is open, the car stumbles and stalls - if I let off as it begins to stumble, it will return to idle. I can slowly open the throttle and the engine will smoothly rev without stalling. If the choke is closed, it will rev quickly just as you'd expect - it only begins to stumble after its at normal operating temp.
Things I've tried:
Checked/adjusted float level +-1/16" from specs - no change - went back to original 1 3/32"
Checked accelerator pump diaphragm and confirmed correct measurement between roll pin and diaphragm cover (3/16" if I remember correctly)
Tried moving roll pin to "lo" position on accelerator pump lever
Adjusted vent valve rod so notch lines up with valve port
Confirmed suggested mixture screw setting (1 1/2 turns out from lightly seated) and experimented turning it both ways Confirmed check balls and weight were installed and used compressed air to clean passages
Confirmed dashpot setting (lightly seated plus 3 1/2 turns in)
Changed jet from 69 to Ford manual suggested 67
Checked for vacuum leaks at bottom of carb
Checked timing and experimented from +12 to +16 with no noticeable change
Ran brand new fuel from gas cam straight to fuel pump
Changed plugs again (ones that came out were covered in black carbon)
I've had the carb on and off the car and opened up probably 10 times - I checked/recheckedfloat level and smooth needle operation several times- I've even changed the accelerator pump diaphragm (even though the one that came out was brand new and looked fine)
I'm stumped....I need some help from all you guys that are way smarter with more experience!
Thank You in advance!
My problem is:
When I quickly open the throttle from idle when the engine is warm and choke is open, the car stumbles and stalls - if I let off as it begins to stumble, it will return to idle. I can slowly open the throttle and the engine will smoothly rev without stalling. If the choke is closed, it will rev quickly just as you'd expect - it only begins to stumble after its at normal operating temp.
Things I've tried:
Checked/adjusted float level +-1/16" from specs - no change - went back to original 1 3/32"
Checked accelerator pump diaphragm and confirmed correct measurement between roll pin and diaphragm cover (3/16" if I remember correctly)
Tried moving roll pin to "lo" position on accelerator pump lever
Adjusted vent valve rod so notch lines up with valve port
Confirmed suggested mixture screw setting (1 1/2 turns out from lightly seated) and experimented turning it both ways Confirmed check balls and weight were installed and used compressed air to clean passages
Confirmed dashpot setting (lightly seated plus 3 1/2 turns in)
Changed jet from 69 to Ford manual suggested 67
Checked for vacuum leaks at bottom of carb
Checked timing and experimented from +12 to +16 with no noticeable change
Ran brand new fuel from gas cam straight to fuel pump
Changed plugs again (ones that came out were covered in black carbon)
I've had the carb on and off the car and opened up probably 10 times - I checked/recheckedfloat level and smooth needle operation several times- I've even changed the accelerator pump diaphragm (even though the one that came out was brand new and looked fine)
I'm stumped....I need some help from all you guys that are way smarter with more experience!
Thank You in advance!