1101 accelerator pump not working

[paulw]

I've got a rebuilt Autolite 1101 with a bad accelerator pump. The car bogs/stalls when you stomp the pedal, but otherwise runs/idles fine. Is it possible to just replace the accelerator pump? Can it be sourced seperate from a complete rebuild kit? Any other ideas?

Paul W.
68 Mustang

 

[fordconvert]

There are a lot of things that could cause that.
You should be able to see the fuel squirting down the throat when you stroke the throttle (engine not running). Typical is at least 2 full squirts before the bowl runs out. IF the motor is cold you will have to hold the choke open to see it. Individual parts are likely available but would end up costing the same as the kit and take a long time to get. The pump involves at least 4 parts that are all in the kit. Kits are less $30

Napa Echlin kit #2-5579

 

[CZLN6]

Howdy Paul:

In addition to fordconvert offered, here are my thoughts and, as usual, more question.

Check the function of the accelerator pump squirt with the engine off. IF the engine is warm at all it is safest to use a mirror to look down the air intake to watch the function of the squirter. An untimely back-fire can do alot of damage to a head in the wrong place.

You said that carb is a rebuild. How old is the rebuild? Did you disassemble and inspect it before installing it? Is the float level set accurately? What distributor are you using? Choke? Are there any vacuum leaks?

Assuming that the ignition is in good shape and carb was properly rebuilt and all parts are correct and there, consider that if the accelerator pump is inoperative- why? Dirt/contamination? wear? Most likely that if the Accelerator pump is worn that badly the rest of the carb is likely in need of a good cleaning and refreshing also. My suggestion is to get a kit, do a good cleaning and check all settings.

Also check your initial advance. Too little can cause an off idle stumble.

IS this carb on a '68 head? How did you adapt to fit it?

Adios, David

 

[paulw]

Thanks for the quick replies. I bought the carb on ebay. It looks very clean with a rebuilders sticker on it. Previous owner said it worked fine, he switched to a 2 barrel. When I look down the throat and pump, fuel just barely dribbles out. I did think about the float levels being off, but it runs so nicely otherwise, that I didn't put that first on the list. I was hoping to try replacing the pump first because of the lack of a strong squirt of fuel.

I screwed up the rebuild of the cars previous holley 1940 so badly that I'm hesitant to tear this one apart more than I need to. So, can I just unscrew the pump from the carb and replace the diaphram? Or should I shell out $300 to have Pony Carbs make it right? Or is that 1101 much simplier than the holley and should I attempt a rebuild? Other ideas?

Yes, the 69 1101 carb is on a 68 1100 base. I enlarged the adaptor plate opening so the butterflies would open. Which leads me to another question. If my memory is correct, the carb has two little channels on it's base, while the base plate only has one. How critical are those little channels? Perhaps some sort of vacuum channel?


PS. I've rebuilt a couple of Edlebrock Weber 4 barrels and they seemed a lot easier than that darn 1940!

Paul W.
Torrance, CA
1968 Mustang

 

[fordconvert]

The 1100 is pretty simple. No metering rods or hangars to mess with and try to align. If the pump diaphragm was leaking it should leak externally. My guess is the problem is in the check balls and or weight which you get to by lifting the top off. I cant remember for sure but it could also be the top gasket is on wrong and not connecting the passages right. I dont remember having to mess with the float just removing the top. The napa echlin kit has a exploded view showing the balls and such that are involved. I think it even comes with the balls but not the weight. There may also be more than one style of top gasket so you have to match them up to make sure you got all the holes you need in the right places. I could be thinking of a different carb but I know the 1100 is one of the easier ones I have worked on.

Just for the heck of it have you tried adjusting the bolt on the pump? Maybe the PO just backed it off?

 

[CZLN6]

Howdy Bck Paul:

Go for it! The 1101 is a much simpler carb than the 1940. About the only carb simpler to rebuild might be the earlier, and smaller side bowl Holleys and the Autolite 2100 2 barrels.

The vacuum channels in the base plate are not critical to your application. If you ground into them when adapting for the 1101, just make sure they are plugged and sealed.

Fordconvert wrote- "Just for the heck of it have you tried adjusting the bolt on the pump? Maybe the PO just backed it off?

What bolt??? Are you talking about the roll pin pivot holes?

Adios, David

 

[fordconvert]

Howdy Bck Paul:
Fordconvert wrote- "Just for the heck of it have you tried adjusting the bolt on the pump? Maybe the PO just backed it off?

What bolt??? Are you talking about the roll pin pivot holes?

Adios, David

Oops, I was thinking the pump had one like the dashpot.

 

[Bort62]

Check to see that the ACC diaphragm is compressing fully when you open the throttle.

You may simply have a linkage issue. You can bend the relevant linkage rod to make sure you get full travel.