timing issue or electrical?

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I didn't get any sound on your video but it looks like you have a bad hesitation judging by the tach. As long as your manifold vacuum is good, acc pump is squirting good and immediate, and your initial timing is at least 10 degrees BTDC, you probably have a vacuum advance problem or other distributor glitch. You might also want to check for timing chain stretch. Put a timing light on it and see what it does under the same acceleration test.
 
It sounds to me like a classic accelerator pump issue. With the car not running look down in the carb and snap the throttle open with your hand and look for an "instant" shot of gas. If you don't see it you may need to make an adjustment. You should see gas as soon as you move the throttle.
 
Sure does.

Badsport said:
It sounds to me like a classic accelerator pump issue. With the car not running look down in the carb and snap the throttle open with your hand and look for an "instant" shot of gas. If you don't see it you may need to make an adjustment. You should see gas as soon as you move the throttle.
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When you rebuilt the carb, did you run your finger in the accelerator pump hole to see if it had any ridges. I had to "ream" mine out once with my finger and a piece of 220 grit to get the little ridges out before. It does sound like an accelorator issue to me as well.
 
Flat spot lack of fuel also looks like your throttle is sticking.How tight is the throttle shaft could be a vacuum leak there.
 
challenger_moe said:
its not the accelerator pump it works fine. need to check timing and see if there is a vac leak
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Define working. Just because it moves, does not mean it's functioning properly. Did you check for pump shot?

You need to see an instant shot of gas when opening the throttle. If you do not see that, that is what is causing the flat spot.

The problem in your vid without a doubt sounds like you have a flat spot when you hit the gas.

By the way, what carb are we looking at here?
 
We know you said you rebuilt the carb, and the accel pump is fine,, but did you actually take Badsports, and others advice, and look for an instant shot of gas?, Carbs often need tweeking,, a screw,, a bend of linkage,, etc..

Now, if this is the original prob that you did all the work for,.. maybe just a tweek of the accel pump linkage is all that's nec.. my .02 .. cheers
 
Has it EVER worked good in it's present configuration? If not, there could be many other causes not the least of which is cam profile and/or or timing. What's the idle intake manifold vacuum reading? Which engine, carb combo do you have?
 
cudamark said:
Has it EVER worked good in it's present configuration? If not, there could be many other causes not the least of which is cam profile and/or or timing. What's the idle intake manifold vacuum reading? Which engine, carb combo do you have?
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its getting a shot of gas, its a /6, 225 with a holley 1920 on it. Couldn't tell you if it ran properly before due to I just bought it a week ago and it has been that way all along. After the carb rebuild and swapping out plugs, wires, and rotor "no cap" it seems to be better but still does it.
 
challenger_moe said:
its getting a shot of gas,
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Instantly, as soon as you move the throttle? This is the critical point here. If you move the throttle you are going to see gas, the difference is, Is it instant or do you get slight movement and then see gas.

I don't mean to keep harping on this but I have listened to the video 3 times and that sure as I'm sitting here that is what it sounds like.
 
What Badsport, myself, and others are trying to tell you is, that for years people have been coming to our business's, taking us out to their vehicle, and demonstrating what you just did,,, and after the first few dozen, you kinda get to know, and proceed to repair their hesitation, by doing nec accell pump work,, by tweeking or what-ever..

So it is Very important that you see gas IMMEDIATELY, the very instant the throttle is moved..

You don't seem to be able to look down the carb, and just see.., and then answer..
Very frustrating when trying to help..

is the shot, - immediate, strong, weak, spluttery
 
well for the first time in going out to see how much gas I was getting in a shot, I got nothing! then tried again and got a nice strong shot. Wonder if the other times it was jsut a flluke that it was working everytime I tried it before. Finished installing wheel bearings and took it for a drive with no issues then pulling into the driveway it sputtered and died. Guess I am going to have to pull the carb apart again. sorry for the frustration.

inertia said:
What Badsport, myself, and others are trying to tell you is, that for years people have been coming to our business's, taking us out to their vehicle, and demonstrating what you just did,,, and after the first few dozen, you kinda get to know, and proceed to repair their hesitation, by doing nec accell pump work,, by tweeking or what-ever..

So it is Very important that you see gas IMMEDIATELY, the very instant the throttle is moved..

You don't seem to be able to look down the carb, and just see.., and then answer..
Very frustrating when trying to help..

is the shot, - immediate, strong, weak, spluttery
Click to expand...
 
You may be able to just bend the arm that operates the pump, try that first. Bend it just a little at a time until you see gas immediately when you open the throttle.

You essentially are trying to get the acc. pump to move quicker.

Post a pic of the carb if you can.
 
What Badsport said,... and - I'm not sure which carb you've got,, but when you diss-assembled it,, did you end up with a little silver ball rolling across your work-space,, some accel pumps had a check valve/ball, to keep the pump circuit full,, other-wise the fuel drains back into fuel bowl, and you'd need 1 pump to fill the circuit, and the second pump to squirt.. (sort of)..

thnx for lookin..
 
Badsport said:
You may be able to just bend the arm that operates the pump, try that first. Bend it just a little at a time until you see gas immediately when you open the throttle.

You essentially are trying to get the acc. pump to move quicker.

Post a pic of the carb if you can.
Click to expand...
sorry for the delay photbucket was not being nice.
100_1495.jpg

100_1494.jpg

100_1493.jpg

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If memory serves me, I can't quite see,, but the rod going up to the plastic cam,, that pulls the accel pump arm,, at the bottom has diff holes for rod,, choose the hole that gives the longest stroke to the pump..

and about that check ball, I can't remember,, but check your diagram.. there may be a ball under your shooter...

Badsport? you have any idea on check-ball???

where's Dan when u need him... DAN ! !

I just checked a service manual,, it suggest the middle hole,, but try others,, and I don't see a ball, but check your exploded view.. but thats what you gatta mess with.. good luck
 
On a 1920 the check ball is captured inside the metering block. It's removeable by driving it out, and the brass cap that holds it, with a small drift or punch. There is an access hole on the bottom of the cavity in the metering block. I'd make sure the kit has a replacment ball and brass cap before removing it however as I don't think they're available separately. If the car has been sitting for ages and the metering block is really crusty, you may have to just get a new one. I wouldn't bend the pump linkage on one of those except as a last resort. There are different holes to try on the linkage to get the right amount of squirt at the right time. The only reason to bend the linkage would be to correct a previous bend or to account for some wear. Keep in mind that the linkage doesn't push on the accelerator pump in that model (like the Carter), it releases the pump diaphram shaft so an internal spring can push the diaphram. With that design, all you need the linkage to do is pull the diaphram shaft out far enough for enough movement to produce a good shot of fuel. The squirt should start emmediately regardless of setting but the setting will determine the amount of fuel that the pump will put out.
 
cudamark said:
On a 1920 the check ball is captured inside the metering block. It's removeable by driving it out, and the brass cap that holds it, with a small drift or punch. There is an access hole on the bottom of the cavity in the metering block. I'd make sure the kit has a replacment ball and brass cap before removing it however as I don't think they're available separately. If the car has been sitting for ages and the metering block is really crusty, you may have to just get a new one. I wouldn't bend the pump linkage on one of those except as a last resort. There are different holes to try on the linkage to get the right amount of squirt at the right time. The only reason to bend the linkage would be to correct a previous bend or to account for some wear. Keep in mind that the linkage doesn't push on the accelerator pump in that model (like the Carter), it releases the pump diaphram shaft so an internal spring can push the diaphram. With that design, all you need the linkage to do is pull the diaphram shaft out far enough for enough movement to produce a good shot of fuel. The squirt should start emmediately regardless of setting but the setting will determine the amount of fuel that the pump will put out.
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kit has a replacement ball but no brass cap.
 
If you're carefull knocking out the plug, you should be able to reuse it. You just need it to fit tight enough so that it doesn't pop out.
 
How does it idle? My 69 slant w/ Holley 1920 always idled a bit rough and slowed way down and wanted to die in D or R. In fact, it would die sometimes when you tried to leave a red light, which my wife did not like. I would often drive with 2 feet and goose the throttle (accel pump worked fine). Went thru ~4 carbs (all 1920) over decades before I found one that ran perfect. I think there is no way to inspect or rebuild the metering block, so many bad rebuilt ones out there. I have a Carter BBS on my 64 slant and the engine idles so smooth you can hardly tell it is running.
 
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