Throttle kills, mix problem?

[schaferstephen]

Hey all,

Having some problems with my '65 200 cid long 6. A few weeks ago, I was driving - thought I ran out of gas. Engine started sputtering when I'd hit the gas, stall, and die. Went to a gas station only to find I was only a few gallons away from full (fuel gauge doesn't work). Seemed fine after that. Then, I started having another problem. After driving about 15 minutes, I'd lose a lot of power. If I hit the throttle to hold speed around 50-60mph, the engine would sputter and stall.

Let me jump in here to say that I have an AC compressor that doesn't work. My friend suggested bypassing it. I took off the old belts, and put on a new one that bypasses the AC. Stopped squeaking! Then when it got quiet, I noticed a miss. Sounds like 2 cylinders are missing. Like a genius, I decided to mess with the mixture to see if it'd help. Because... I'm so smart like that... Right now, I can barely tap the throttle without making the engine stall. Sounds like it's flooding. Tried leaning it back out, to no avail. Not sure where to go from here.

Fyi, it's an automatic, and it has some type of Holley carb on it... not sure what kind, the tag is gone Here are pics.

Thanks SO much for your help everybody!! Yawl are lifesavers.

Also... I'm pretty ignorant about this carb. I don't know how to adjust the choke... pretty pathetic Couldn't figure out what type of carb it was, so I can' tget much info on it

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[ludwig]

Unless your choke is drifting shut, I would look at the fuel supply. Specifically, if it ran or runs well and then slowly starves out, and then dies completely only to start again later, the intake screen in the tank may be clogging up with debris in the the fuel tank. Typically, when this happens, rust flakes or dirt but usually rust sheets will get stuck to the outside of the screen. When you stop they fall off only to get stuck on the screen again as the fuel is sucked up.
Another thing you might consider is installing a clear plastic fuel filter ahead of the carb and the filter in the carb. Which makes me think that you should look at the fuel filter that is attached to the end of the fuel line where it goes into the carb to check for contamination.

If you have contamination anywhere along there, you have to get the tank cleaned out. No big deal. Just empty it and have it boiled out at a radiator shop.

 

[bubba22349]

You could reset the idle mix to 1 1/2 turns out from lightly seated that should be close enough to run. Then you should also do a compression test to see what condition the engine is in.

 

[JackFish]

Also look for a vacuum leak. Check all the connections.
Check the carb mount by grabbing the carb and see if it moves around at all.
Mine had the adapter screws come loose, and was stalling out unless I really revved it.
I first thought it was a failing fuel pump.

 

[Xargon321]

you migt think about rebuilding the carb as well it might be something internal like the accelerator pump. if its dumping to much fuel in at once it might cause it to flood when you lightly step on the gas.

 

[nachoman]

Mine did this a few months ago - turned out to be oil fouled spark plugs because of dried valve stem seals. I figured this out after changing the fuel pump.

A few years ago, i had a similar problem - because I had a burned exhauset valve and a dead cylinder.

My guess is that your problem is probably ignition related or engine/mechanical related and not fuel related. Pull your plugs and check them. Check the distributor cap and wires. Check compression. If everything is good with those, then tear into the carb.

 

[schaferstephen]

Ok all, here's an update:

Carb rebuild resulted in a rebuilt carb with a broken choke, because I'm a klutz and dropped the bimetallic element by accident. Hopefully will be going get an autolite 1100 from a local gentleman tomorrow.

I'm going to replace the vacuum hose from the distributor to the carb as well, it got torn up removing the carb.

I have a brand new fuel tank installed, but I'm going to replace the sending unit as well as the filter between the fuel line and pump.

Man oh man... I really hope I don't have any burnt valves. I'd really prefer to not have to deal with any of that. Knowing my luck though...

Thanks so much for all the input everybody!!

 

[schaferstephen]

Ok, here's the update. Got an autolite 1100 and I put it on, ran AWESOME. Still going to replace the sender etc, but it ran fine with one catch. Has a slight miss. My friend has the same engine in his car, and has the EXACT SAME MISS. Possibly it's premature to say exact same... but it sure seems like it. He's rebuild his engine from tha oil pan up and never got rid of it. Never seems to get any worse, but it's still... there. Anybody have any experience with this?