> I see -- a way to tell if an empty bowl causes the stall. Definitely a
> great idea, but I'm not sure I can get a view down into this carb. It has a
> built-in right-angle throat. Maybe I can do it with an inspection mirror and
> flashlight. And would the accellerator pump work on this carb if the engine
> is shut down -- someone pointed out that engine vacuum actuates the
> accellerator pump on this carb.
It's been at least 20 years since I've worked on an early Jeep carb, so I don't remember
how the accelerator pump is configured. However, it is certainly possible that you have a
vacuum-actuated piston that delivers a brief squirt of fuel when it senses a rapid drop in
manifold vacuum (aka, rise in manifold pressure), OR a rapid rise in venturi vacuum (drop
in venturi pressure). The sensing circuit on this type of accelerator pump often has a
"bleeder" circuit that allows the pump piston to quickly return to its original position,
even when the throttle is held open for a long period of time. This allows a preliminary
squirt for a part-throttle opening, and another squirt when the throttle is opened
further. Anyway, there are SEVERAL variations on this approach. One advantage to the
vacuum-actuated accelerator pump is that it provides somewhat better proportioning of
enrichment, since it's reaction speed is determined more by engine need rather than how
quickly you punch the gas pedal to the metal.
The vast majority of newer carbs use mechanical linkages to the accelerator pump diaphram
or piston.
If you could e-mail or FAX me a diagram of the carburetor, I'd be able to tell for sure
how it's set up.
Anyway, if you can't actuate the accelerator pump without the engine running, then just
unscrew the top of the carb immediately after the engine stalls and see if there's fuel in
the bowl. If the bowl is empty and the fuel pump is pumping OK in terms of pressure and
volume, then it points to the float or float valve assembly.
Carry on...
Alan
(Salt Lake City, Utah)
===
To unsubscribe from the mil-veh mailing list, send the single word
UNSUBSCRIBE in the body of a message to <mil-veh-request@skylee.com>.