carb re-build ?

[xirdneh]

Every now and then a Tercel begins to idle a bit rough and mileage drops a bit so I pull the carb and re-build it with a carb kit. That usually solves the problem. If the carb was re-built within the last year or two I'll disassemble it and clean it without using the re-build kit but the success rate is not as high as using a re-build kit.
In January I used a re-build kit on two carbs and just disassembled and cleaned three others. The two kit re-builds worked fine while the three no-kit cleaned ones idled rough.

What is the most likly cause of this?

I re-use gaskets if they look good and use new gaskets left over from past kits that supplied extra gaskets.
I dunk all the parts in a gallon can of stinky carb cleaner over night.
I check the fuel solenoid "o" rings and only re-use them if they are still pliable.
Still it seems as though i'm missing something. Obviously.

On a good idling carb looking down the on top of the carb I can hardly see the gas as it is misting somewhat and the carb is quiet. On a poor idling carb the gas is dripping and things are wet down there and the carb is noisy.

[takza]

I have a poor idling carb that has gone 60K miles...and a carb rebuild kit still in the package.

My last mistake was getting water into the vent tube that apparently vents the bowl while decarboning it. Carbs DON'T like water?

Went thru all the vac lines and snugged up a bunch...doing OK now...except it dies at a stop sign now and then (just 1X)...when I had the air cleaner off...the gas level was barely visible...guess the float/inlet valve are/were having issues. No likey water....?

I've rebuilt them before...but know it is an iffy thing. A slightly rough idle is something I can live with. Mileage has remained the same or better.