[fortjosh]

Does anyone have any advice on how to fix a Autolite 1100 1v carburetor with a power valve assembly that gets stuck in the up/depressed position?

details/hints:
I have my dad's 67 Mustang with 200 six and rebuilt the carburetor in 2009, 2 time in 40 years. The problem is that there is no fuel from the accelerator pump when I press the gas pedal. The carb is getting fuel, it isn't the float or fuel pump. It will run if you can use enough starter fluid to get it running, but will hesitate and die if you step on the gas too fast. You can slowly accelerate

I took apart the carburetor and noticed that the power valve assembly was frozen (the part is integral to the upper half of the carburetor, and is adjacent to the main jet pickup in the bowl). It is basically a rod holding a ball bearing, and there is a return spring. I sprayed it several times with cleaner and worked it back and forth, and it seemed to be working, but occasionally it gets stuck in the up position. I reinstalled it and it worked once, then it got stuck closed again. There does not appear to be any way to remove it easily, and it is reportedly a "non-removable part" and is not covered by any of the rebuild kits I have seen, however, I am not a pro.

if I pump the gas with the upper carb housing off, fuel does shoot up out of one of the holes, so I assume the diaphragm is fine.

I am at a loss, but I am thinking I will take the upper assembly to a carb shop to see if they can rebuild it or if soaking it in their industrial strength cleaner will help.

Any other suggestions would be appreciated. thanks.

 

[Explorer]

I fought this same problem. Took me three try's tearing down the carb, including soaking in a gal of carb cleaner overnite, before it finally stayed free. Been running now for a year now with no more problems. The last time, I sprayed it with PB Blaster and let it set. Not saying that's what did it, but it's working.

 

[fortjosh]

Thanks, I will try it and give it a few days then. Carquest sells a gallon container with dip basket. I didn't do that when I rebuilt it the 2nd time. Hopefully it is varnish in there causing it to stick.
thanks a million!

 

[Explorer]

Read the directions on which product you buy. I think the Gunk kit say's no more than 4 hr soak, but I was able to leave overnite. Berrymans I believe is stronger and may eat up things if left too long. Some of it you can actually see it boiling the stuff off. Any of it you need to remove any plastic parts.

 

[fortjosh]

You are spot on regarding the directions. I soaked it for 30 min, looked clean, but still no squirt, but the power valve assembly worked much better as you predicted. I took the carb apart for a 3rd time, and pumped it by hand slowly, and traced the passages that gas was supposed to flow in, and they all appeared clean. The smallest diameter hole is the actual nozzle in the throat of the carb, I tried squirting carb cleaner in it and it wouldn't come out the other side, it would shoot back out. I took a small needle and poked into the nozzle, and it cleaned it up. Thanks!

 

[Explorer]

Hope it works out. Thanks for following up.