ChattanoogaJSB

All I can say at this early juncture before a drive is that with the mixture screws closed pulling up on the disconnected pump **** off the engine, and it was noticeably activated as it was set up previously.

The AP would at least be a constant metered source of fuel. I can't say just yet that it solved all life's problems but I can say that it was adjusted incorrectly. Will report back.

Westlotorn

This is not as complete as the old Carter Carb manual but it does give some good ideas for Carter Carb issues.
http://www.crankshaftcoalition.com/w...uild_guide.pdf

I found the Federal-Mogul Carter AFB Fine Tuning Manual copy on line. When FM owned Carter Carbs in the 80's this manual was very popular.

MikeM

The only time the AP is supplying fuel to the engine is when the plunger is MOVING down. At steady idle, it supplies nothing unless something is amiss.

PS. If I remember right you can put that S link on the pump plunger backwards and it will bind the pump in the bore.

W Guy

Benton,
When you set the AP height, did you back off the idle adjustment screw all the way and close the throttle arm fully? My adjustment spec is 33/64" from the lid to the top of the pump rod.
As Mike said, the position of the pump has nothing to do with fuel delivery while it's sitting still. Your car was NOT idling based on the position of the pump.
Do you notice any fuel dripping from the primary venturi clusters when it's idling?

Verne

fuely

Benton, is the heat riser on the exhaust free and opening?

fuely

Benton, have you checked that the heat riser at the exhaust is free. Is you can screw the idle jets all the way in and not kill the motor it would seem that air is getting in somewhere. Paul

ChattanoogaJSB

It is wired open, yes sir. I'm not running any choke.

ChattanoogaJSB

Verne- I did adjust the idle all the way back yes. I set the plunger to 1/2." I believe this was the service manual height. Despite the fact that earlier I was able to kill engine by pulling up on it, this has not solved the problem entirely. Most of you knew that.

MikeM

To those that know. Is there a check ball in the AP circuit that moves off it's seat when the pump actuates and lets the gas go in the venturi?

Is he missing something that lets the AP well bleed into the carb?

I can't remember. I'm stabbing in the dark.

W Guy

Mike,
There is a check ball there at the bottom of the pump bore but it's purpose is to prevent fuel from being pushed back into the bowls when the AP is pushed down. IF it's defective, there wouldn't be any pump shot from the two squirters above. There is a check needle below the squirters that shuts off the fuel flow (by its own weight) to prevent fuel from leaking back into the pump bore.

Benton's problem seems to be a rich idle issue, which should not be caused by any function of the accelerator pump. I am completely mystified by his statement that the engine died when he manually pulled up the AP.

That is why I asked him if he made certain the throttle arm was completely closed when he did his adjustment. He only said the screw was all the way backed off. That's also why I asked him if he saw fuel dripping from the primary venturis at idle. He did not answer that.

Benton, IF you see fuel from those venturis, your throttle blades are not able to close fully or be set at the correct position for idle. They are exposing the transfer slot which allows more fuel/air to be sucked in to the engine. The fact that your idle raised when you turned in the mixture screws indicates an over rich condition which you reduced by closing off the amount of extra fuel/air from the idle port.

The reason for all of that is most likely a clogged/blocked idle air bleed or by-pass port in the venturi cluster(s). If that happens, you'll have a rich mixture but not enough air velocity to obtain a good idle rpm. You compensate for that by opening the throttle more which opens the transfer circuit to get more fuel/air, but it's still too rich.
I know you said you pulled the clusters and washed them down with solvent, but I don't think you fixed the problem. Use a very fine wire and route out those ports. Then spray a solvent with a spray tube to be sure it passes through and out of the bottom of the cluster. You can also follow-up with compressed air to be sure they are open.

Verne

Wear safety glasses.

ChattanoogaJSB

Hello Verne- thanks to you and mike for more follow up! I have not seen any leaking fuel, but I have seen the tops of the primary "butterflies" are - at times- splattered with fuel.

I have to go do some family stuff this evening but the responses have been so good I didn't want you to think I wasn't most appreciative.

I did have the throttle "closed" forcefully when I adjusted the plunger. The armature doesn't quite meet the fully retracted main idle screw head before it stops (if that makes sense). Maybe stops 1/16 from there.

I will try cleaning the clusters again- may drop them in the carb cleaner bucket to soak overnight!

Thanks again!

Benton

MikeM

Me too!

vettepoor

Benton - What Verne said about cleaning idle passages with wire is good advice. I was having problems with the choke passage on my wcfb, and no amount of soaking in today's solution worked. I ended up using fine piano wire to unplug things - no problem since! The carb soaking stuff today is just not as effective as the good old cleaning solvent the flaps used to carry. Good luck.

John

XLR8OR

You may want to check the harmonic balancer. It is possible that the outer ring has slipped in relation to the inner ring, making the index location incorrect (happened to me). I suggest verifying Top Dead Center (TDC) to check and make sure the degree marker is really at TDC. You can get one from Jegs:

(http://www.jegs.com/i/Proform/778/66...ductId=1268409)

Westlotorn

A back yard trick we used many times to get a carb working again. I will share this and then duck because I know it is way out of left field but a mechanic friend taught me this 40 years ago and I tell you it has fixed 50% of carb idle issues I have had in cars and boats.

Don't read if you are weak of heart.

It takes two people comfortable around engines. One to run the engine and one to stand by with a thick towel, about a 2'x2' towel minimum size.
The air cleaner is removed and if it has a screw sticking up to mount the air cleaner take it off also.
The driver revs the engine to about 3,000 RPM at operating temperature.
The driver gives the buddy the sign he is about to floor it.
Driver floors it and before the engine is allowed to rev much higher the buddy covers the entire carb with the towel, folded up so it is a couple inches thick choking off the air supply.
The driver keeps his foot on the floor so the carb is wide open.
This done correctly will starve 95% of the air intake and the engine will bog down heavily.
Just before it dies out completely remove the towel. The driver will have to be fully able to listen and react as the engine recovers and starts to rev again. The driver must back off the throttle. Run it at 2,500 a minute or so to clear out all the fuel you just vacuumed in then back off to idle and see if it is working better. Sometimes it is better but still not right so do the process again, I have done some 3 times before it idled well again, just make sure the engine is fully recovered and burning clean before each attempt.
Doing this creates so much internal vacuum that it pulls small obstructions right trough all the small passages in the carb washing it clean.
Sometimes there are problems with worn out parts or a large obstruction that this won't help at all but you would be amazed how many times it will work to fix a plugged passage in a carb.
Now I will duck and take my beatings. A mistake doing this could very easily over rev the engine, that is the reason for my advice, 2 experienced people at the controls.
Catching the towel in the belts could be a real danger zone, see above, experienced people would avoid that.
I have probably done this on 25 cars over the years on cars with carb idle issues. 50% of the time they just purr afterwards. If it does not work you only wasted a little time and .50 in fuel and you are back to pulling the carb for repair.

MikeM

I have had some success in the past with this trick, Mark.

Frankie the Fink

And when you're done grab the handles of the wheelbarrow you used to carry your b@lls around so that you can go off to do other chores

ChattanoogaJSB

Mark- that is a crazy trick that as you said has apparently been around forever but I'm too green to have heard of.

I tell you what- I'm bold enough to try it! But I'll need to enlist a capable friend as you say.

In the mean time I'm soaking the parts shown as I think I was directed in my gallon of carb cleaner - I have usually gone overnight with it but he car says half an hour. I may blow them out in an hour or so, and strip a bare wire (from my electrical kit) to run through.

Also I wanted to attempt to show those interested how much "slot" is below the butterfly... Definitely a "hair" with most of the slot well above.

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W Guy

Don't forget to ream this one too. (in the red circle) Also run a wire up through the bottom of the emulsion tube.
Verne

Frankie the Fink

And don't be surprised if you don't have that horizontal, spring looking thing between those carb throats. That's a hot idle compensator and not on all models -- Right W. Guy ?