Might be time for a tune up, new plugs, fuel filter, pcv valve, cap and rotor and wires if aplicable.
Engine dieseling Runs too hot or idles to fast Try leaving in gear when shutting off
Check timing. idle could also be set too low (rpms) so vibration is increased.
When you are parked or in neutral while the car idles, your engine will shake. The vehicle will also get poor gas milage. Bad gas can also cause engine failure.
Acceleration Cable broken broken, you dump!
Adjust the idle screw.
zyou tps might be bad
On my Chevy truck it idles high when its low on antifreeze but if its not that more than likely its usually a vacuum line loose or cracked. good luck.
If the engine idles and revs up okay in neutral, it is likely the torque converter clutch lock up solenoid.
why does my 4.75 BRIGGS & STRATTON lawnmower engine idles high and low when cutting my grass
I also wish someone would answer this question as my 1997 Ford contour does the same thing. It shakes and vibrates very bad when it idles and it idles really low. They set the idle up to make it so it wouldn't die so now when I start it it revs up really bad then it idles down then it idles down to low and shakes I also wish someone would answer this question as my 1997 Ford contour does the same thing. It shakes and vibrates very bad when it idles and it idles really low. They set the idle up to make it so it wouldn't die so now when I start it it revs up really bad then it idles down then it idles down to low and shakes
Needs a Tune up
Need a little more info. What Model and year of the vehicle?