I have a 91 civic. Just cleaned the IACV and tightened the FITV. Car ran good for a couple days. Now when I try to start the car it turns over but dies immediately due to almost no idle. When I leave it sit for a couple hours and try again it will run VERY rough for 7-10 seconds then the rpms slowly drop and it dies and will not start back up. It ran fine prior to adjusting the FITV and cleaning the IACV. coolant and oil is full. Battery cable has a loose connection but appears to function just fine. Aftermarket AEM intake. Any advice would be appreciated. I live in WI and we had a huge blizzard, the morning after that is when problems started. I had driven the car just fine the night before.

EDIT: when I start it after it's been sitting if I give it gas it will try to keep itself running but slowly die.

 

Nobody?

 

Vacuum leak maybe? Not 100%, but my throttle body gaskets causing mine to do same thing on occasion.

 

Turns out it was dirty spark plugs. Idle is still low so I will replace my IACV/FITV but it runs now! Who would have that!