Sounds like you need to clean your carburetor.
Before messing with the carburetor, check the fuel filter - it might be clogged.
The cause of high engine idle and surges in the 1989 Corvette is due to..Read More
Where is the location of the idle screw on the Briggs and Stratton 6.0 engine mulcher mower?
Check throttle positioning sensor.
Idle adjustment set to high
engine idle set too high or the timing is off and needs reset.
Engine idle too high.
Vacuum leek
low idle and uneven idle
High idle, misfire, check engine light,High idle, misfire, check engine light,
There are several things that can cause high idle. An older carbureted engine may have a vacuum leak or sticking choke linkage. Newer computer controlled engines have an idle control device called an idle motor which could be faulty or receiving bad information from other sensors on the engine ( IE. temperature sensor ).
whats the problem for my 94 ford van engine high and low idle
the choke is on