Rep Power: 0

first off i am new to the forms so please excuse me if i am posting in the wrong area.

i just recently bought a 1996 honda civic dx hatchback, 5 speed transmission and 113xxx on the clock. when not in gear it idles pretty low around 500 rpms, when i tap the gas sometimes i drops even lower almost like its going to stall. when i am driving and shifting out of any gear the rpms will remain the same. like as a example. if im in 3rd going 40 and at 3000 rpms, if i push it the clutch, tranny in neutral, the rpms will stay at 3000 rpms for a few seconds then slowly descend back to a good 900rpm idle.. i was thinking iac? if anyone has had this problem and knows whats wrong and how to fix it, any and all information is apprichated. thanks

 
Rep Power: 156

is your Check Engine Light on?

When the car is cold, check your coolant level, add as needed, You might want to bleed the coolant system and see if that helps. if it's low or air is in the system, the IACV will not work properly.

It could also be clogged, you can take if off and clean it out with brake cleaner, but make sure to re-bleed the coolant after installing it.

 
Rep Power: 0

No cel. But I noticed the rpms would return to normal at a dead stop. So I out the front up on my Buddy's lift, put it into 3rd and reved it to 3000rpms and at 40mph it stayed reving untill 0 mphs. So Iuin plugged my speed sensor and just like that the rpms are normal. Meaning when I left off the gas they always return to a nice 900 idle. Any ideas on the problem

Edit; I cleaned it out, wasn't dirty at all. And coolant is perfect

 
Rep Power: 0

I replaced my IAC and nothing changed. Still same problem. Any ideas

 
Rep Power: 156

did you bleed the coolant system after changing the IACV? sometimes it takes awhile.

 
Rep Power: 0

Yes it was exactly the same. Nothing changed for the better or worse

also just replaced the speed sensor and nada. same thing.