Lumbergh

I have a 1968 Coupe with a 289 with the 2V Carburetor. I believe that I have the accelerator pump linkage adjusted properly and the pump does supply gas, just not as quickly as it needs to. When I open the throttle, while under the hood (engine off), it frees the spring to move the armature on the accelerator pump that depresses the diaphragm supplying the fuel to the carb. Unfortunately, it does it in about as much time as it takes to read that long complex compound sentence describing it. Is it possible that the spring is sprung? I can't find a listing for a replacement spring at the suppliers I normally search. Can you even by this spring? Within the next two years I plan to upgrade to a dual plane Edelbrock intake and a 4V carb, but I'd rather not live with the hesitation when starting from a stop that I now have. Thanks for any help you can give me.

socalwrench

There should be an adjustment for how quickly the accel. pump moves, and it's directly connected to the movement of the butterfllies. So, you're looking for a replacement spring for the accel. pump? It's a 2v, so is it a 2100 or 2150? Most carb kits will include a new accel. pump and spring. I'm having some difficulty understanding what you're asking for.

2+2GT

Does the engine bog and die when you stomp on the gas? If the answer is no, then you don't have a problem.

Lumbergh

There are two adjustments for the accelerator pump on the carb. They appear to adjust how soon it begins reacting to the throttle and how far the armature travels as it depresses the diaphragm in the accelerator pump. I have it adjusted so it will begin reacting as soon as the throttle begins to open. What is bothering me is when you open the throttle, it allows a spring to move the armature that depresses the diaphragm in the accelerator pump. This is the spring I am talking about. This seems to take longer than it should, resulting in some serious (IMO) hesitation when leaving a stoplight, etc. I could figure out how to add pictures of the carb to my post, if that would help.

This is the only car I've had with an accelerator pump on the carb. My other classic doesn't have one and all of my other cars have been fuel injected, no carb. If having the engine bog down then catch once the main carb catches up to the now fully open air flow, what is the point in having an accelerator pump?

Lumbergh

This is the only car I've had with an accelerator pump on the carb. My other classic doesn't have one, and all of my other cars have been fuel injected, no carb. If having the engine bog down then catch once the main carb catches up to the now fully open air flow is normal, what is the point in having an accelerator pump? With the engine off, if you manually activate the accelerator pump, you can hear the injection of gas, so it seems to be doing the job of supplying gas, but it seems to take too long in doing it, resulting in a stuttering start unless I rev the engine a little (while keeping my foot on the brake, of course) to get it past that initial fuel starvation before I actually want to go. If this is normal, I'd like to improve on it by increasing the speed at which the accelerator pump delivers its little shot of gas.

kalli

from what you describe you look at the antistall dashput, not the accellerator pump:

antistall dashpot is big and just as you describe when you floor it the thing will move slowly out and when you close the throttle it will land back on it

the accellerator pump is under the carb and works the other way around the more you open the throttle the more it presses the lnikage against the pump

anti-stall dashpot:



accellerator pump:



under the wooden piece for showing is the accellerator pump lever, that pushes the pump right under the carburetor upwards to squirt fuel.
This is activated via a linkage with spring adjustment above the wooden thingie going to throttle

here's what the lot looks like taken out including the pump cam.

can we clarify this first? and what exact carb is it? pictures

Lumbergh

I believe it is a 2100 carb, which is configured totally different from the one in the lower picture. The accelerator pump is on the front of the carb with the antistall dashpot as shown in the first picture. Strange that the first picture does not show the accelerator pump, though. I am as certain as I can be that I have the original carb, tag and all. I will take some pictures when I get home tonight and post those to clear things up.

2+2GT

Impossible. A carbureted gasoline engine with no pump would die every time you hit the throttle. You must be referring to something else. Ford carbs have integral accelerator pumps. So do Chevys, and Volvos, and Hudson Hornets…

kalli

yes, pictures would be great. firsst picture is autolite 2100/4100, second picture is a holley.
on the first picture i believe the acc pump is at the very top, not sure.

Lumbergh

The picture below shows the carb from above with the spring in question circled. Shouldn't this spring act quickly to move the arm to depress the diaphragm delivering a shot of gas inorder to avoid hesitation when accelerating from a stop? Is this spring part of a standard carb rebuild kit? Are any adjustments of the spring itself possible? Thanks for your help.