My 99 civic Ex (D16Y8) starts perfectly when cold (up to 2000-down to 1500 then 1500 till operation temp) *idle is smooth*

When war it goes to 1500 then 1000 then 670 *and idle is very rough*


I'm new to manual transmissions but:

If I go to neutral when slowing down my idle will stay at 1000 until I COMPLETLY stop... (Shouldn't it drop to idle?) (is there even a speed sensor?)


I also get a missfire code (PO301/302/300)when accelerating if idle is not 100% warm (never when cruising or at temp) I have NO CLUE why this would be!

TPS has been checked (9 TPS value) good voltage

IACV works (at least it moves when jumped)

I also want to bring my idle up from 670 (I feel it is too low) but I can't cause it would mess with my other sensors TPS which is as high as it should be...

Please Help Me!

 

670 is right on for idle speed.......Check/change your spark plugs/distributor cap/wires for the misfire