96 legacy 2.2, recently switched itself to 2,000rpm idle and takes 5 seconds for rpm to drop enough to match up next gear.( dropping very slow) 296k iac valve need cleaned or worse?

look for an open vac line.

this sounds like an air leak.

didn't find any problems of what I can see with vac lines, checking manual to see if I missed any

vac lines seem to be fine.

Does it idle that high on cold start? Does the idle stay that high when the engine is warm? Or is it just hanging between shifts?

 

Replace the PCV valve if it hasn't been done recently. Check all the breather and PCV hoses for splits. Be sure to check the hose to the MAP sensor, and the hoses under the manifold to the purge solenoid.

 

Could have a stuck Nuetral position switch on the trans. It's the furthest back of the two switches on the side of the trans. Follow the wire up to the bellhousing and unplug it. Check the switch for changing continuity as you move the shifter in and out of gear.

it is idling a shade high when cold, just before coming to a complete stop, it'll drop down to near 1250rpm. replaced pcv today with no changes. rpm hang when I take off without warming car since I got it, always went away within a few miles.whatever it is must have been on way out

both o2 sensors are gone, but have turned 4k miles without problems. car has no check engine light

it is idling a shade high when cold, just before coming to a complete stop, it'll drop down to near 1250rpm. replaced pcv today with no changes. rpm hang when I take off without warming car since I got it, always went away within a few miles.whatever it is must have been on way out

 

High idle until the car is warmed up is %100 normal.

 

Colder the morning, the more pronounced this effect will be, the longer it will hold this sustained idle.  Can make for unwanted acceleration on manual vehichles if you take off right away.

ran for a good hour, drove fast, sat in garage, was plenty warmed up. takes almost 10 seconds for rpm to drop from 4,ooo to 2,5oo. gonna start pulling vac lines tomorrow

Manually open the throttle body and see how long it takes to close back completely, should be almost instantaneous. You may have some corrosion building up making throttle closing slow. If it passes the first part, have a helper do the same thing with the accelerator pedal while you watch the throttle body.

ran for a good hour, drove fast, sat in garage, was plenty warmed up. takes almost 10 seconds for rpm to drop from 4,ooo to 2,5oo. gonna start pulling vac lines tomorrow

 

When it's doing this, grab the IAC hose and pinch it closed....see if the idle drops.

 

If it does.....that's a stuck open IAC.  Which means a weak "close" coil.....

 

So Vacuum pulls it nearly closed........but not all the way....and not quickly like when IAC works proper.