About 1/64" from bottoming out when throttle is wide open.
Im guessing you have a carb, the accelerator pump is in it.
Carb needs adjustment? Accelerator pump needs replacement? Choke needs adjustment? If you have a diesel you might want to check the glow plugs.
32mm keihin with accelerator pump
Pump is on front of Carb. square panel with four screws.
On my engine,the accelerator pump on the Carb is going bad, 350 engine with quadrajet carb
first of all is it injectors or carb, if a carb it could be a bad accelerator pump
if it runs fine until you push the gas pedal the accelerator pump may be bad if it has a carb on it.
a double pumper is a 4 barrel carb. commonly made by holley. they were called this because they have two accelerator pumps. one on each float bowl on either end of the carb. most carbs do not have this feature, they usually only have one accelerator pump.
carb problem my guess would be accelerator pump or stuck power valves in carb.
make sure the timing is right, no vacuum leaks, or the carb could have a bad accelerator pump in it.
Could be a bad accelerator pump Could be a bad choke adjustment
If it has a carb. (not fuel injected) one possible cause could be a bad accelerator pump (located in carb.).