idel problem
 

i got a 89 crx with a zc motor sometimes it idels fine but sometimes it idels up and down what can cause this thanks

vacum leaks, low coolant, iac valve,
intake manifold gasket, tps

:dito: If everything slim mentioned checks out then try tweaking the idle screw, it fixed the same problem on my 1991.

thanks will try but sometimes the vehicle is running 100 percent and then it starts to idel like this up and down ,then i give it gas its perfect when i let go it idels like that again and to make it go away i turn if off and let it sit for an hour and start it again and its perfect dont understand also i had the vehicle parked for a year without starting it

i got the exact same idle problem, (zc motor in 91 si) i was thinking it was the timing, but it does need coolant, so im gonna top that up before i do anything...

same problem here, gotta check those things out

sounds like its only acting weird only when the engine is warm?
i was having a similar problem on my civ...it was my iacv

triz

thats true when the engine warms up thats when it starts to idel like that up and down how much is a ic valve and where is it located thanks

its located on the back of the intake manifold near the throttle body. It has 2 coolant hoses attached to the bottom of it. I think a new IACV from honda is around $300.....might want to grab a used one.

I just recently have been getting this problem. My idle is fine most of the time but then all of a sudden it jumps randomly, happens while cruizing as well. My Tach will show a jump in RPM's but it doesn't actually sound like my car is reving higher when I see the jump on my tach. Mine is a 2nd Gen B16. If anyone narrows it down please post it.

Thanks

Also check to make sure you didnt get the IAT and IACV plugs reversed with each other.

Weird thing about my problem is that it doesn't happen all the time. It happened earlier today around noon where my idle was fluctuating and now its gone. I just replaced my PCV and plugs. I checked for vaccuum and Intake manifold leaks with some carb cleaner, nothing there. Tomorow I am going to take off the IACV and see if its clogged or really dirty.

i have a similar issue...

Hey Martin when I had this problem in ended up being my Ignitor. I have one for sale if you need it. I ended up changing my whole distributor which also fixed the problem, but changing just the ignitor does the trick too.

Re: idel problem
 

does it go away when it warms up?