Carb 1questions!

[66Sprinter]

I have an 1101 from Pony that is 1.75" on the throat. I also own a Weber progressive 2bbl. In the last month, I have bad hesitation from launch and in any gear. It starts, idles and revs incredible..as always. But under load..she bogs bad enough to die. I have checked plugs, dizzy, vacuum lines, etc. I finally found a bad gasket between the carb and adaptor. I replaced the carb gasket, but still have the problem. Is this a power valve problem?

Also, I am going to purchase adaptors from Mike but I have a question that fits both carbs. On the mating side of the 1101 carb (to adaptor) there is a small canal the ports to the throat. I assume is for the idle circuit. On the 2bbl there are two holes in key positions also ported to the throat, I assume is for the same.

When I look at the adaptors from Mike, I do not see the mirror image canal. When I looked at my old 1bbl spacer (with the coolant tube) it is there.

What exactly is this canal for?

Lastly, If I get the vaporizer adaptor that mates a 1.5 to 1.75 on the intake....will it still work well with my 1.75 1101?

Thanks...Jim

 

[CZLN6]

Howdy Jim:

Q- "But under load..she bogs bad enough to die. I have checked plugs, dizzy, vacuum lines, etc. I finally found a bad gasket between the carb and adaptor. I replaced the carb gasket, but still have the problem. Is this a power valve problem?"
A- Most likely is that the accelerator pump has died. A good cleaning and a rebuild kit should fix it for the 1101.

Adios, David

 

[fordconvert]

Its been a while since I worked on one but seems like I remember the passage for the choke being in the base and using the wrong gasket or having it flipped would leave the choke not working.

Accelerator pump, power valve, or timing issue. When you hit the throttle and put the engine under load the vacuum drops. This is where the power valve comes in, it opens a larger passage to let more fuel in vs. the amount of vacuum. If this does not happen engine goes lean till the vacuum comes back up and can get enough fuel from the regular jets. The other thing is the timing. There is always the issue of the load o and the scv not being paired up together and then the issue of the vacuum component in the dizzy not working. Many of the aftermarket vacuum cans are sort of one size fits all and have way too much range and too fast a response time. Back in the day these were pretty specifically tailored for each car to get the desired response. Thats one reason manifold vs ported vacuum works on some setups and not on others. If you are running manifold vac you could have your base timing too far retarded so when the vac signal drops the timing is too retarded. If you are running ported you could have the base too far advanced so when you tip in the throttle it pulls in too much advance.

 

[66Sprinter]

Thanks guys...I am getting the rebuild stuff ordered.

The only thing that changed in the setup was the occurence of hesitation. No timing, issues, plugs or vacuum leaks or changes when the symptom occured. I had started running Seafoam..maybe it knocked something loose...but I use two filters for gas..so I would expect no issues with debris...

Preciate it...I am going to remake the carb adaptor to better than what I have....then with the rebuilt carb...it shoudl be great.again...

Jim

 

[66 Fastback]

If I recall, the port in the stock adapter just feeds manifold vacuum to certain circuits in the carb. I think there was a hole and passage in the base of the carb and its associated gasket that lined up with the passage on the stock adaptor. I would question whether or not the carb would operate correctly if it was set on an adaptor that did not have the passage for it to sense the manifold vac.
Doug

 

[66Sprinter]

Doug, '

Thats in the area of my thinking. A passage is not really designed for fuel, but the route from the throat to the hole is for vacuum. So when I make my new adaptor..I will make the passage also, and make sure my homemade gasket has the hole for it.

THanks...jim

 

[ludwig]

I don't remember exactly, but if it is not for the idle circuit, that little passage is probably for the choke vacuum to suck the heated air from the manifold tube to the pull-off spring. This wouldn't be needed if there was an electric or hot water choke pull-off (as in later models).