QuestionI have an 84 Corolla 4AC carb engine, 149K. Recently it started holding a high idle after it warms up. Starts easily, choke sets and kicks off easily, idles fine just after I tap off the choke and am setting. Then when I take off and the
engine gets to operating temp it holds a continous high idle - enough to do 25 mph without touching the pedal. Continues to do so after I put it in park. I checked for vacuum leak around carb area an did not find anything obvious.
Sometimes, but rarely, it will come to normal idle after I brake to a stop. I have factory shop manual and could do some troubleshooting if I had a starting point but I'm not sure where to begin...
AnswerWhats a Carb?
Just kidding, dont see them to much anymore.
The secondary throttle plate usally doesnt close all the way.It gets gummed up.
Its the plate at the bottom of the carb.
Youll need to hold the top plate open and get an old tooth brush. sray carb clener down to it and work the throttl open to close.
When yoouve got it clean, lube her up with some type of 3-1 oil.
The other thing I used to see is a bad AAP diaphram. Its on the carb. Vac line to it.3 screws. Pull the vac line off and see if theres fuel in the line. If so, the diapram has ruptured and needs to be replaced.
That should be illustrated in yopur manual.
Check them and let me know.
Mike
