'67 327 idle issues

[jpcoutts]

My '67 with an AMC 327 is giving me fits trying to adjust the idle. If I attempt to set the idle any where near the spec it dies. I have to set the idle somewhere close to what the normal fast idle would be to keep it running without having to feather the pedal. I disassembled, cleaned and put it back together with no change. I have always has an issue with the float level on this carb and wonder if that could be part of the issue. Any suggestions?

[wiley-moeracing]

Sounds like a vacuum leak somewhere.

[jpcoutts]

Good thought! The carb is really old and is a likely candidate for being warped and there is plenty of old dry hard tubing to look at. I don't want to replace the carb, but it may be unavoidable. I guess I'll try spray some carb cleaner or WD40 around on the carb and see if that makes any difference.

[tgreese]

Good thought! The carb is really old and is a likely candidate for being warped and there is plenty of old dry hard tubing to look at. I don't want to replace the carb, but it may be unavoidable. I guess I'll try spray some carb cleaner or WD40 around on the carb and see if that makes any difference.

Wear around the throttle shaft is a common source of vacuum leak. Then idle will change as you push the linkage around. BTDT. A carb shop can bush the carb body to tighten up the shaft. Get in there with a mechanic's stethoscope and listen.

[jpcoutts]

I gave the throttle shafts a good look and there doesn't see to be much play in the fit. The truck was a low mileage service/plow truck and excessive wear hasn't been one of the issues I've had to deal with - much. I'm afraid the carb needs more than a good cleaning, when I took the top off to look at the float level there looked to be a lot of corrosion inside the carb bowl and I'm sure it's like that in places I can't see. I also noticed that the choke parts/linkages may not be put together correctly, I'm the guilty party!, so I'm going to keep trying and see if I can get it back together properly and reset the float. I read my TSM about setting the float and I know it isn't correct the way it is. The float level seems not high enough when set to spec and I'll need to bend the float arm to get it right, I hope it doesn't break!

[jpcoutts]

I think it's time to replace the carb. I want to stick a stock replacement. Is there any where to get one better than the local Mcparts store? I've looked around and don't see many options.

[tgreese]

I think it's time to replace the carb. I want to stick a stock replacement. Is there any where to get one better than the local Mcparts store? I've looked around and don't see many options.

Carb shop? Maybe not local to you, but these places that specialize in carburetors seem to do a good job. They would rebuild your core.

The big remanufacturers break down all the cores they get into bins of parts. Then they build carburetors to a spec, replenishing stock as needed. Somebody makes a list of all cars that can use the same carburetor, minimizing the numbers needed for coverage. With the small volume sold, I would not trust that process today.

[mud89]

I think it's time to replace the carb. I want to stick a stock replacement. Is there any where to get one better than the local Mcparts store? I've looked around and don't see many options.

I had issues with mine too, i eventually bought one on ebay , stock replacement, it was a NOS or a rebuilt carb i don't remember exactly

Of course they don't pop up on ebay every day..

[Cliff]

Several years ago a buddy needed a carb for his '67 AMC Rebel with a 327. He said only Rock Auto was able to supply the proper stock replacement carb. He tried a few from local stores but something was always wrong with the linkage. The carb from Rock Auto was 100% correct.

[tgreese]

http://www.earlycj5.com/xf_cj5/index.php?threads/restored-yf.121719/

[jpcoutts]

The body of this carb appears to be corroded (the interior surfaces are rough and covered with grainy residue) and I don't know if a rebuild will take care of that. I wonder if gas with ethanol was a cause part of that issue?

[tgreese]

I expect that a carb shop would bead blast the carb body. They can also reapply a factory-style chromate coating. These carb bodies are typically a zinc alloy die casting (some variant of zamac). This material is chosen because it is economical and corrosion resistant. However, I noticed these carbs will develop pits with a bloom of some kind of oxide erupting from the pits. Grainy, as you describe. Not sure what this comes from, since the zinc is supposed to resist corrosion from water.

I have rebuilt carbs with this grainy appearance, and just left it alone. Does not seem to affect performance. The carb shop can take the corrosion off, and likely can replace the carb body if needed. I'd give them a call and ask.

[jpcoutts]

I've been sidetracked from the carb issues by a flat. One of the wheels was badly rusted and ruined the tube. I'll post about that separately. Always something!