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Ok so I cleaned the carb, use some fuel cleaning additive (Which made a surprising difference, sounds and runs way smoother now) and then re-tuned the carb.

Car is great until its warm. Here is idle 2 minuets after cold start. Video Link. Very steady idle

Here after about 10 minuets of running (temp gauge broken fwi) Video Link . Jumping around a lot, didn't get on video but occasionally drops to 500rpm.

I put an infared temp sensor on each of the cylinders' exhaust outputs. The driver's half of the engine was between 200 and 250 and the passenger side half was showing around 300 and even 375 on one of them. I immediately shut the car off.


Thank you for your input!
 

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I'd like to see the temp at the thermostat housing.

The roughness could be from many factors, careful tuning of the carb and ignition will tell.
 

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Discussion Starter #5
I'd like to see the temp at the thermostat housing.

The roughness could be from many factors, careful tuning of the carb and ignition will tell.
Get a timing light and set the ignition timing.
Then adjust the idle mixture screws.
Then set the idle speed.

A vacuum gauge could be helpful too.
If it's been sitting a while, likely the carb and the radiator are clogged. If the gas tank is old, it could be full of crud.
Alright I have the carb apart. All the gaskets look like they need to be replaced. Idk if maybe one of you guys can see something I don't or suggest something.

I should also note that turning the idle mix screws all the way does not shut the engine off.

Anyone have any ideas? Or should I just go buy a new carb and not deal with it.

Here are some pictures of the carb: images
 

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Rebuild the carb, kits are cheap. Follow the instructions and you’re good to go. I think jumping to buying a new carb is a last resort and likely overkill.
 

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That's a basic 750 vacuum secondary Holley. Very easy carb to rebuild, hardest part is getting the old gasket material off. Make sure you use carb clean and compressed air to clean ALL the passages. If you've never done it before, just take your time and do one thing at a time. Lots of how to sites and videos that cover the process, or you can get a How to Rebuild your Holley CArb book that'll have even more details.

Rebuild kits are cheap, yours being a 3310-6, you need the 37-754 renew kit

 

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Discussion Starter #8
That's a basic 750 vacuum secondary Holley. Very easy carb to rebuild, hardest part is getting the old gasket material off. Make sure you use carb clean and compressed air to clean ALL the passages. If you've never done it before, just take your time and do one thing at a time. Lots of how to sites and videos that cover the process, or you can get a How to Rebuild your Holley CArb book that'll have even more details.

Rebuild kits are cheap, yours being a 3310-6, you need the 37-754 renew kit

The kit you mention here doesn't seem right. I confirmed that is the correct model for the carb. That kit however is missing a gasket for the secondary float bowl.

I tried a 4160 carb kit from local advance Auto parts and found that out the hard way. My worry with buying these kits online is that it's not gonna be what I need.
 

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The kit you mention here doesn't seem right. I confirmed that is the correct model for the carb. That kit however is missing a gasket for the secondary float bowl.

I tried a 4160 carb kit from local advance Auto parts and found that out the hard way. My worry with buying these kits online is that it's not gonna be what I need.
Just looked back at your pics - someone added a secondary metering block to your carburetor. The 3310-6 should have a secondary metering plate. You'll need to get an extra bowl gasket and might want to talk to Holley tech about which metering block gasket you need.
 

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4150 has 2 metering blocks. 4160 has one (if memory serves me correctly). My initial thought on this "runs good when cold, rough when it heats up" issue was the choke... but that's just me.
 

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4150 has 2 metering blocks. 4160 has one (if memory serves me correctly). My initial thought on this "runs good when cold, rough when it heats up" issue was the choke... but that's just me.
Thank you for the information! As for the choke, it is disconnected and off.
 

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Actually I think this is the carb I have except sombody added a secondary metering block. So I just need to find another gasket for it...or remove the metering block altogether. Thoughts?
See post #9

Just looked back at your pics - someone added a secondary metering block to your carburetor. The 3310-6 should have a secondary metering plate. You'll need to get an extra bowl gasket and might want to talk to Holley tech about which metering block gasket you need.
 

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Discussion Starter #16
See post #9
Just looked back at your pics - someone added a secondary metering block to your carburetor. The 3310-6 should have a secondary metering plate. You'll need to get an extra bowl gasket and might want to talk to Holley tech about which metering block gasket you need.
Woah, totaly missed that. Never heard of this metering plate. Definitely don't have one. Maybe I should just remove the added metering block restoring the carb to stock and all my problems will go away.
 

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Thank you for the information! As for the choke, it is disconnected and off.
… well, now that the carb is out, yes, that makes sense, but was the choke disconnected and off when you were running the engine?
Before you start the engine you're supposed to pump the pedal once (or twice) before turning the key. This closes the choke. When you first start the engine the choke opens up 1/8". if you have an electric choke, as the engine gets hotter, it opens up until it's wide open when the engine gets up to 195 degrees. Manual choke, well, you have to do that manually.
If the choke is "disconnected and off" then the engine is starving for O2 when it heats up.
Too much fuel=too much heat, and rough idle.
Make sense?
 

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Discussion Starter #18
… well, now that the carb is out, yes, that makes sense, but was the choke disconnected and off when you were running the engine?
Before you start the engine you're supposed to pump the pedal once (or twice) before turning the key. This closes the choke. When you first start the engine the choke opens up 1/8". if you have an electric choke, as the engine gets hotter, it opens up until it's wide open when the engine gets up to 195 degrees. Manual choke, well, you have to do that manually.
If the choke is "disconnected and off" then the engine is starving for O2 when it heats up.
Too much fuel=too much heat, and rough idle.
Make sense?
It's manual. And it was disconnected while on the engine. I just gave it some gas until it warmed up.

Pretty sure the idle mix screws weren't doing anything.
 

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Idle screws won't do very much unless the engine is up to 195 degrees and the choke is wide open.
 

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Idle screws won't do very much unless the engine is up to 195 degrees and the choke is wide open.
Choke is always wide open in my case. Turning them all the way in didn't kill the engine. Plus it was running hot, that's what started this whole escapade. Partly I just want to buy a new carb but I also feel like I need to get to the bottom of this one.
 
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