Hey i got a 1993 civic coupe dx with the original d15 non vtec motor. Im having and idling problem along with (its auto soon to be stick) when im holding the brake down in drive it the car jerks with the idle at a stop. Now i checked my iac for the problem and i found that no coolant is getting to the iac. Now i bleed the systems a couple times and its still the same and i also changed the iac also. Please Help

 

Car jerking at idle can be caused by the a/c compressor cycling on and off, that is if you have a/c. IACV doesnt even need coolant going to it, unless you are in subzero freezing climates, so very doubtful thats your problem.

Try cleaning the IACV first. If no luck there and you are still convinced its IACV related, you may have to try a known good one.

 

The IACV definetly needs coolant flow. If you dont have flow you wont idle, check and make sure you have coolant flow through you FITV fast idle thermo valve. it or another hose could be restricted causing your issue. I have fixed a bunch of these idle issued on a bunch of diff honda engines and they are all just a little different. Good luck

 

Absolutely false. Go disconnect the coolant hoses on yours right now and see what happens.

 

yup i dont run the coolant hoses on my iacv. just idles off on the first start up

 

I don't run coolant line 2 my iac also idles just fine

 

Coolant flow thru the IACV is needed for the same reason the coolant flows through the throttle body. Its only for freezing temps to prevent those mechanical devices from becoming frozen/stuck. Ive bypassed both on my car as I live in so cal.