[Charlie D.]

I posted a question on this forum but I can not find it so I thought I would try again.
1967 Mustang 289 w/2 barrel carburetor. What is this called, what is it for and how should it be set? Currently it is adjusted away from the accelerator pump to have any impact on it. Linkage goes behind the acc. lever and covers the hole on top of the carb with a rubber pad.

 

[Klutch]

That's an early Autolite 2100 with a check valve atop the fuel bowl. It should stay closed when the carb is at idle. It should open when the accelerator is pressed. My '69 Cougar had a carb like that. I think the check valve is to allow fuel in the bowl to flow easier under acceleration, but I'm not sure.

 

[Charlie D.]

Thanks for that answer. Owned it for a few months and now almost ready for cruising. The way it is now it stays closed 100% of the time. The bottom of the linkage is behind the acc. pump lever, does not contact it and no way for it to open. IF the linkage was in front of the acc. pump lever then it would function as you said. Doesn't seem to have any effect if I open it with my finger at idle.

Another question: Timing is set for best idle and max, vacuum of 19-20", idle set at about 675 RPM's but surges up about 200 RPM's and then back to 675. Engine hot or cold makes no difference. Slight movement of the distributor by hand does not stop it.

 

[ylexot]

That's actually a late 2100 feature. It is an emissions device so raw gas is not simply ventilated like on the earlier carbs. This came in from Late 67 and remained until the 2100D (Motorcraft) design obsoleted it. When you actuate the linkage, it should just kick the tang when the pedal is released. Here is the correct assembly from Bob Mannel's book.

 

[Woodchuck]

Yep. That's the bowl vent.

 

[Charlie D.]

Thanks guys but how is it supposed to work. The end of the linage goes behind the acc. pump lever, as I believe it should but

That's actually a late 2100 feature. It is an emissions device so raw gas is not simply ventilated like on the earlier carbs. This came in from Late 67 and remained until the 2100D (Motorcraft) design obsoleted it. When you actuate the linkage, it should just kick the tang when the pedal is released. Here is the correct assembly from Bob Mannel's book.

View attachment 748871

The linkage stays closed all the time and does not contact the acc. pump lever. Am I correct in saying that I need to adjust the linkage so that the hole is open all the time at idle and drops to closed when I step on the gas then reopens when I let off? Seems backwards for an emission item. That would be the only way it would move.

 

[Charlie D.]

Another question: What if it is permanently blocked off?

 

[Woodchuck]

Thanks guys but how is it supposed to work. The end of the linage goes behind the acc. pump lever, as I believe it should but

The linkage stays closed all the time and does not contact the acc. pump lever. Am I correct in saying that I need to adjust the linkage so that the hole is open all the time at idle and drops to closed when I step on the gas then reopens when I let off? Seems backwards for an emission item. That would be the only way it would move.

Seems backward, but the reason is because at idle there is little fuel flow and usually not a lot of sloshing around. When the throttle is opened, fuel starts flowing and sloshing around in the bowl, making vapors.

What if it stays plugged? Depends on whether the top cover gasket you're using is blocking off the bowl vents in the air horn or not... I've seen old crusty 2100's with just the hole in the cover all plugged to crap and still running.

 

[ylexot]

It only kicks the lever on release. It uses the over-travel to do this. Manually push your linkage on the carb wide open, then let go. You should see it kick. Earlier models just had a small hole. This hole is bigger on yours, but is covered by the rubber plug on the arm. There is also the return spring on the arm you can see in the left hand side of the picture. As long as the arm is almost or barely contacting the ACC pump extension, you should be all right.

 

[Charlie D.]

Me again. The specification sheet for a 1967 289 engine with 2100 carb has different float settings.
One says "289 engine with automatic w/o TE is 31/64".
Then there is a setting for 289 automatic with TE'. What does the TE mean?

 

[daves67ss]

thermactor emission control. It's to control smog..Air injection into the exhaust manifolds. It was a way to burn the emissions before they made it into the outside air.

 

[Charlie D.]

Thanks much for all the help you guys have given me.

 

[Charlie D.]

UPDATE: finally got the vent linkage straightened out.

 

[Charlie D.]

I have been looking at replacing my carburetor and would like to stay with the Motorcraft 2100. Found lot's on line but they have the electric choke and I would prefer not to have to modify. They also have a diaphragm hooked to them and mine doesn't. Will it work if I don't hook it up? Will my existing thermostat cover work if it fits?
Second question: Everything I have found on line has connections at the carb. for cable throttle and I would like to keep the existing rod to carb. if possible. I do see on pictures of replacements that there is a hole next to the cable ball on the carb. that I am thinking the rod would connect.

 

[Charlie D.]

Another question for the carb guys. Spent a lot of time trying to set the high idle cam when cold. Seems to work pretty good. After engine has come to a full warm up and shut down the engine has trouble starting when warm. Have to pump the accelerator several times. Carb has been rebuilt.

 

[Klutch]

If your carb has been rebuilt, why do you want to replace it?

Warm starting is a classic issue with early Mustangs.

 

[Charlie D.]

If your carb has been rebuilt, why do you want to replace it?

Warm starting is a classic issue with early Mustangs.

Not wanting to replace. Seeking info. about starting after warm up.