idle jump
 

hey people,
i just got this one question, my cars runnin great but recently, my idle jumped from about 850 to 1500, now when the car is at even operating temp, the idle is 1500, it runs fine and is smooth and constant at that idle but, it used to be about 850 so i was just wondering what anyone thinks it could be. The car is bone stock, and a 94 touring. thanks for the help.

check for vacume leaks, a hose that has popped off can cause the idle to jump.

I have EXACTLY the same problem and have been searching for vaccum leaks. I can't find any and in fact, all hoses have been replaced to silicon.....????

I hope we can find this problem soon....!!

Have you pulled any ECU codes? High idle can be caused by a number of things. A vac leak, a bad Idle Control Solenoid, throttle cable binding or too tight, or just crud in the throttle body keeping the butterfly open.

Vac leaks can be tough to spot. Some people suggest getting a can of carb cleaner with a straw on the nozzle and spraying it around the intake manifold. It should get sucked in and cause an idle surge when directed at the vac leak.

One annoying place for the vac leak is at the lower intake manifold gasket. but if it came on suddenly, then a LIM leak is not overly likely (but still a possibility).

See the following pages for suggestions:

http://www.scuderiaciriani.com/rx7/idle_adjustment.html

Hehehe, use a non-flamable brake cleaner, not carb cleaner which can light up with all the heat from your engine.

The brake cleaner will smell real bad if it is sucked into any of the vaccuum lines and burns up.