Post by palestein9 on Sept 4, 2012 18:03:25 GMT -8
BIG NEWS! I was able to get my stock Aisan carb. running the way it's supposed to! I played around with this thing for years with rough idling without any major breakthrough. I love the car, but I was ready to push it off a cliff! Then the idea came to check the float. What made me think of the float? Because every time I took it out to clean the carb., I had it out for at least an hour befor re-installing it. The car ran nicely for a few hours then it went back to running badly. A week later I pulled it apart again with the same result. Then it occurred to me from working with my Triumph TR4 that the float in the Celica might be the problem, because the float in the TR was pinholed, causing the same type problem I was having with the Celica: Then BINGO! It occurred to me that Celica float, bing made of some type of porous plastic, would have enough time to "dry out," and everything would be fine - for a while - but then it would begin to sink after a short time, causing the same problem. The float had become "gasoline logged" but I didn't realize it. Of course it would sink to its own level of neutral bouyancy after being immersed in gasoline once again, causing too much gas to get past the needle valve, and I'd have the same old rough idle. I have some old parts listings and ordered out a new float and put it in and end of problem! The Toyota part no. is 21209-33011 for the 20R & 21209-38011 for the 18R. They're probably about the same. Also, I discovered that the tiny spring (21864-26020) from inside the needle valve was missing, compounding the rough idle problems. It's a two stage valve and the spring likey came out at some point during past attempts to put things right. I didn't know there was a spring in there. It might be better to get the update valve from a rebuilding kit. One other thing: The gas level on these carbs. should show half way up on the glass window in front. Mine showed no gasoline line because it was all the way filled! What I was looking at WAS gasoline! I had to experiment with bending the float tabs to get the level right. As a last check, look into the top of the carb while the car is idling. There should be no visible gas spray at fast idle. If there is, there's too much gas being dumped into the carb, either from a soggy thirty year old float or a bad needle valve. Also, check the tiny mesh fuel strainer just inside the input of the needle valve and blast it out with carb cleaner. As far as the business of these carbs. is concerned, I've never heard of anyone reporting back that they solved the chronic rough idle problems that plague these cars by replacing the float. That could be ninety percent of the problems with these units. By the way, I replaced the AAP diaphragm too, but mine wasn't really bad, but they do go out in time. I hope this info helps someone out there. By the way - does anyone have any ideas re. the fuel cutoff solenoid? Mine works, but it causes a flat spot @2600-3000RPM unless it's unscrewd several threads. It never used to do this. Any ideas? 
