Weird Idle Question

[import racer]

I've noticed lately when i pull up to a stop sign that the tach would go up to almost 1500 rpm then come back down.I figured I had air in the cooling system so bled it for almost a half hour, but for about 30 seconds it surges up and down continually then it stops.Does anyone have or had this problem or any idea how to fix it.

[2oodoor]

It only takes a few seconds to bleed. You have to make sure the radiator is full and preferably the engine is warm (not hot) as long as the thermostat has opened. Then you slightly open up the bleed screw.
This works better for me when I give it some throttle and shoot a nice stream out of the bleeder and immediately close it

Is this an automatic car or manual? I was going to say that sometimes the throttle cable and clutch cable are tie wrapped together and every time you push in the clutch the throttle cable housing is pulled some.

On an automatic car, if the rpm goes up slightly when coming to a stop it is likely the transmission downshifting as it should.

[import racer]

It's an auto but just started doing this after I changed a hose on the eacv to fast idle.I bypassed the throttle body,Don't need to heat that up.