Okay messed with it again and I put my hand over my throttle body and it died so No vaccum leaks. Plus I used some carb cleaner and no change in idle. If I unplug the eacv/iacv it idle's down and smooth and the cel comes on. The fast idle vavle isn't even plug in and don't ook like it ever was. My coolant is full to the rim and I have a steady stream coming out with no air pockets...LOST

 

What year/engine Civic?

 

Is the engine fully warmed up? Measure the ohms of your coolant temperature sensor, or just replace it. Sounds like the ECU is thinking the engine is cold and increasing the idle. Since it slows down when you unplug the IACV, it is the ECU driving the valve.

 

lol sorry about that b18b1 swap in a 96 civic hb obd1

 

Is the CEL ON?

Try cleaning the FITV on the throttle body. Sounds like it may be stuck open. You can test by placing your finger over the port in the throttle body leading to the FITV. No suction should be evident when the engine is hot.

 

No cel and no sucking when cold or hot. I don't thing it's ever been hooked up and I don't think there's een a thermastat in the car either

 

No thermostat? That's the problem then. The ECU will normally make it idle fast until it warms up. Also it will run rich, causing poor gas mileage and high emissions. So install a thermostat.

 

I will put on on tomorrow My b18b is boosted (gt3076r) no o2 senser it's disabled. tuned on crome. I have a skunk2 intake and one of the coolant lines just go to the iacv and nothing goes to the facv. But it just started doing this when it got cold so idk..