My 91 hatch starts fine. But press on the gas alittle bit and the idle starts jumping up and down. Replaced the whole intake manifold with all the sensors. Ran fine for about two days then started acting up again. I've been to 4 different mechanics and they don't have a clue. If anyone knows how to fix this please let me know.

 

Have you tried cleaning the FITV and IAC?

 

Cleaned them both and no change.

 

Fixed the weird idle problem. New problem now. This happens before my motor is warmed up. If I try and take off fast from 1st gear and my civic doesnt want to go it just sputters. Same thing happens when I downshift. But after the motor warms up back to normal. Any ideas??