The Ford Barn

rhphotord · 05-21-2020, 06:13 PM

Rebuilt this carb for my wife's 66 Mustang with a 289 cu engine
Has horrible hesitation from idle and have to feather the gas to get it moving up to speed. Actaually stalls if pushed too hard from a stop. All new internals...what am I missing here. Never had an isssued like this before rebuild. Ideas ?

wellcraft17 · 05-21-2020, 09:34 PM

Have you looked down the carb venturis while slowly moving the throttle shaft Activating the accelerator pump to see if any gas is being pumped down the throats. Lack of fuel will cause the problem you describe.

scicala · 05-22-2020, 11:09 AM

It sounds like your problem is related to what wellcraft17 said. Also, check to make sure the accelerator pump diaphragm moves inward as soon as the throttle is even slightly opened, and that you have enough diahragm travel. This is adjustable by bending the long rod that goes to the accel. pump lever. There is also an orange rubber check valve that could be leaking behind the diaphragm. Also make sure the coil return spring is installed behind the diaphragm.

Sal

packrat5 · 05-23-2020, 06:07 PM

I am probably repeating what Scicala is saying, but also, there are several different lengths of the " push pin" on the accel pumps. Check your old pump against your new one, to make sure they are the same lengths. The adjustment holes must be correct also, there are several different types and several different combinations. In some kits there are "universal" pumps, and one or two push pin shims that are sometimes missing from the kits, or just ignored as "something extra" in the kit.

rhphotord · 05-29-2020, 02:16 PM

Carb update. Pulled the accelerator pump apart and all parts are intact look fine. Changed the accel. pump drive rod orienation to another link to give it more fuel. Bingo it appears that solved the hesitation. Never would have thought a simple rebuild would incur such a problem. Took an hour, top down ride without an issue. Thanks to all.

scicala · 05-29-2020, 05:06 PM

Sponsored Links (Register now to hide all advertisements)

Thanks for posting the outcome. With carburetors, attention to detail when assembling and making adjustments really pays off.

Sal

05-21-2020, 06:13 PM	#1
rhphotord Senior Member Join Date: May 2010 Location: West Salem, Wi. Posts: 281	Autolite 2100 carb hesitation Rebuilt this carb for my wife's 66 Mustang with a 289 cu engine Has horrible hesitation from idle and have to feather the gas to get it moving up to speed. Actaually stalls if pushed too hard from a stop. All new internals...what am I missing here. Never had an isssued like this before rebuild. Ideas ?

05-21-2020, 09:34 PM	#2
wellcraft17 Senior Member Join Date: Feb 2012 Location: Tampa fl Posts: 130	Re: Autolite 2100 carb hesitation Have you looked down the carb venturis while slowly moving the throttle shaft Activating the accelerator pump to see if any gas is being pumped down the throats. Lack of fuel will cause the problem you describe.

05-22-2020, 11:09 AM	#3
scicala Senior Member Join Date: Jun 2010 Location: Detroit suburb, MI Posts: 3,698	Re: Autolite 2100 carb hesitation It sounds like your problem is related to what wellcraft17 said. Also, check to make sure the accelerator pump diaphragm moves inward as soon as the throttle is even slightly opened, and that you have enough diahragm travel. This is adjustable by bending the long rod that goes to the accel. pump lever. There is also an orange rubber check valve that could be leaking behind the diaphragm. Also make sure the coil return spring is installed behind the diaphragm. Sal

05-23-2020, 06:07 PM	#4
packrat5 BANNED Join Date: Mar 2015 Location: Wisconsin Posts: 301	Re: Autolite 2100 carb hesitation I am probably repeating what Scicala is saying, but also, there are several different lengths of the " push pin" on the accel pumps. Check your old pump against your new one, to make sure they are the same lengths. The adjustment holes must be correct also, there are several different types and several different combinations. In some kits there are "universal" pumps, and one or two push pin shims that are sometimes missing from the kits, or just ignored as "something extra" in the kit.

05-29-2020, 02:16 PM	#5
rhphotord Senior Member Join Date: May 2010 Location: West Salem, Wi. Posts: 281	Re: Autolite 2100 carb hesitation Carb update. Pulled the accelerator pump apart and all parts are intact look fine. Changed the accel. pump drive rod orienation to another link to give it more fuel. Bingo it appears that solved the hesitation. Never would have thought a simple rebuild would incur such a problem. Took an hour, top down ride without an issue. Thanks to all.

05-29-2020, 05:06 PM	#6
scicala Senior Member Join Date: Jun 2010 Location: Detroit suburb, MI Posts: 3,698	Re: Autolite 2100 carb hesitation Sponsored Links (Register now to hide all advertisements) Thanks for posting the outcome. With carburetors, attention to detail when assembling and making adjustments really pays off. Sal