Missing Carb part?

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Warlux

Warlux

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Hey guys,

I have a 67 Dart with a 318 in it. It's my first classic car and I'll start from the beginning for some context. I recently had an accelerator pump diaphragm leak. I have very little carburetor experience but decided to tackle it myself. Unfortunately a previous owner at some point stripped out the diaphragm cover threads and jammed a bunch of copper wire in there to get everything to stay tight. This lead to me replacing the fuel float bowl and adjusting the float level.

I thought it went fairly well, and the car starts, idles, and accelerates well, but when I go to rev match on my downshift, the quick blip on the gas is causing it to bog down and nearly stall out. It never had this issue before.

On to the issue at hand. I got it home and removed the air filter and was just looking at the carb when I noticed a couple places where it looked like "something should be there" and found just a hanging loose piece that seems to me could be used for tension. Fearing that I knocked something off when I was working on it. I googled my carb, compared it to old pictures before the leak, and sure enough it looks like I'm missing a part on top, a flap of some type. I have attached pictures.

My question is, if it ran so well before the leak, was this part removed for a reason? What is this part called and what does it do? Is this the cause of my bogging down when I rev match?

Thanks in advance!
PXL_20220409_151829008.jpg
PXL_20220507_223535838.jpg
 
Pull all that choke junk off the side of the carb. You don’t need it. Just remove the three slotted screws and take all that off. Unless you want to find a choke plate and shaft and put that junk back on.
 
They removed the choke flap...

If you drive it in cold weather, you will need it.... If no cold weather, then you may be able to get away without it...
 
The stud for the accelerator cable is flipped 180°, the part where the throttle cable goes should be on the inside and the long part should have the transmission kick down linkage attached to it...
 
The bog issue. The arm from the accelerator pump diaphragm needs to line up under the head of that large screw w/spring. This allows for adjustment. It looks like your arm is bent and not contacting. Or my old eyes aren't working.
 
Murray said:
The bog issue. The arm from the accelerator pump diaphragm needs to line up under the head of that large screw w/spring. This allows for adjustment. It looks like your arm is bent and not contacting. Or my old eyes aren't working.
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It's hard to tell from the angle and how far out the picture is...
 
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Murray said:
The bog issue. The arm from the accelerator pump diaphragm needs to line up under the head of that large screw w/spring. This allows for adjustment. It looks like your arm is bent and not contacting. Or my old eyes aren't working.
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I replaced both diaphragms, neither arm was bent, it's possible that I knocked into one when I was tightening down the carb and pushed it out of place. I will check that out.
 
krazykuda said:
The stud for the accelerator cable is flipped 180°, the part where the throttle cable goes should be on the inside and the long part should have the transmission kick down linkage attached to it...
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Thanks for pointing out all those things and giving me some info I can research into! The kickdown linkage, is that required with a manual transmission? I will look into the bypassed vacuum line too.
 
Warlux said:
Thanks for pointing out all those things and giving me some info I can research into! The kickdown linkage, is that required with a manual transmission? I will look into the bypassed vacuum line too.
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No, kickdown linkage are for automatics only...
 
As to your original question, you got the pump leak fixed, but the newly found bog is probably from the proper adjustment of said pumps.

This may help with that...

I'm interested in your combo thou. A teen with a single plane, a double pumper and a stick sounds pretty cool. :)
 
OldmanRick said:
I'm interested in your combo thou. A teen with a single plane, a double pumper and a stick sounds pretty cool. :)
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It's a very interesting car. It feels like nothing is original and finding parts can be difficult at times but I think that's half the fun.

It's a Dart 270 with a 318 swapped in at some point, the previous owner left a piece of paper in it with the mods he made to it...

323 Sure Grip Diff
833 4 Speed Overdrive Transmission
Centre force clutch
650 Holley
Edelbrock Streetmaster 318 Intake
360 Exhaust manifolds
RV Cam (Not really sure what this means)

It's a blast to drive (when it's running well lol). I've had it for just over a year now and I feel like it's a great car to learn with. Makes it easier with such a great community here.
 
How did you set the float level? That is important. The fuel level should be at the bottom of the sight plug hole. When you bump the fender fuel should dribble out of the hole when the plug is removed.
F7CC22BB-23BF-4026-9FA5-4480E2469234.png

this is your sight plug for the secondary side. There is one for primary also. As @ratbastad said, what you are missing is the choke flap but you may not need it. If not just remove all of the choke stuff and disregard it. Throttle blip bog could be caused by a few things, accelerator pump adjustment, squirters clogged, float level, way too high, transfer slot sync incorrect. Carb and timing adjustments go hand in hand and I recommend reading as much as you can regarding tuning a Holley before making any significant adjustments. They are simple to tune and the knowledge is good to have.
 
TT5.9mag said:
How did you set the float level? That is important. The fuel level should be at the bottom of the sight plug hole. When you bump the fender fuel should dribble out of the hole when the plug is removed.
View attachment 1715924531
this is your sight plug for the secondary side. There is one for primary also. As @ratbastad said, what you are missing is the choke flap but you may not need it. If not just remove all of the choke stuff and disregard it. Throttle blip bog could be caused by a few things, accelerator pump adjustment, squirters clogged, float level, way too high, transfer slot sync incorrect. Carb and timing adjustments go hand in hand and I recommend reading as much as you can regarding tuning a Holley before making any significant adjustments. They are simple to tune and the knowledge is good to have.
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I did as you said to adjust the float, when I first opened the sight the fuel was pouring out, after about 4 adjustments I opened it and a tiny drop came out and when I hip checked the fender some sloshed out.

I think my next step in troubleshooting is to check the accelerator pump adjustment.

It's a deep rabbit hole getting into the whole carburetor thing...
 
It is but once you understand all of the individual adjustments it’s very easy to set one up. Regards fuel level, when you adjust it, make sure you start the engine after each small adjustment and re check the level. I adjust them with the engine running but that can make a mess if you’re not carful.
 
Update for any future readers.

I found the problem. After trying the suggestions here with no luck, I ended up removing the fuel bowl and accelerator pump diaphragm... And found out that I never installed the orange rubber flap style check valve into the accelerator pump passage. My original one had a built in ball check and I didn't think anything of it before installing the new fuel bowl. It's running great now that the accelerator pump is functioning...

Anyways! Thanks everyone for your time and suggestions! I appreciate it!
 
Warlux said:
Update for any future readers.

I found the problem. After trying the suggestions here with no luck, I ended up removing the fuel bowl and accelerator pump diaphragm... And found out that I never installed the orange rubber flap style check valve into the accelerator pump passage. My original one had a built in ball check and I didn't think anything of it before installing the new fuel bowl. It's running great now that the accelerator pump is functioning...

Anyways! Thanks everyone for your time and suggestions! I appreciate it!
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Yeah, that'll do it! Glad you got it worked out.
 
Warlux said:
Update for any future readers.

I found the problem. After trying the suggestions here with no luck, I ended up removing the fuel bowl and accelerator pump diaphragm... And found out that I never installed the orange rubber flap style check valve into the accelerator pump passage. My original one had a built in ball check and I didn't think anything of it before installing the new fuel bowl. It's running great now that the accelerator pump is functioning...

Anyways! Thanks everyone for your time and suggestions! I appreciate it!
Click to expand...
Thank you for updating us, not everyone comes back to do so. It might help the next guy troubleshooting!
 
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