Hey guys, I picked up a 1st gen CRX (1986) last week for $175. It didnt run, and doesnt have wheels. I got it running by swapping the ECU. When I first started her up, the idle was high (around 2K rpm) but settled down around 1k and would bounce from there between ~700rpm and 2k rpm. I did some research and found that low coolant could cause this bouncing idle.

I topped off the coolant and added some missing hose clamps. This fixed the idle bounce, but now the car starts and continues to idle extremely high. The car goes straight to 4000rpm and I'm not sure why. Is there a way to adjust the idle?

I read some about the Idle Air Control Valve, and cleaning it may help. Does this get clogged? Has anyone done this and seen a difference?

Sorry for the noob questions, I dont usually work on old school cars like this one. I'll try to post a video when I get a chance.

Thanks in advance.

 

please help me!
I got some wheels for her today, but I cant put her on the street revving at 4k all the time!

I'll be painting them soon.

 

You might have more luck posting in the right forum, check out the pre 1988 forum here:

https://honda-tech.com/forums/classic-hondas-106/

Generally though, a high idle like that will be caused by a vacuum leak.

 

Yeah check your vacuum leaks. I dont know if the car haves a FIT (fast idle thermal) valve. Its a coolant valve by the throttle body with 2 coolant hoses, some times they get stuck open and idles high.

good luck and hope this helped.

 

Thanks, Can a mod please move this thread to the appropriate section? I'm sorry I guess I didnt look hard enough.

I'll look into it. Do you know an easy way to find a vacuum leak?

 

make sure the cable isn't stuck, like the gas pedal cable. Start off by simple things.

 

while it was revving high, I put my foot under the pedal and pulled up--nothing. However, I could give it more gas. So I dont think its a cable, but that was a good start. I'll check the other stuff tomorrow hopefully, ive been busy lately, but the car is making great progress from a week ago when i didnt have wheels, and it didnt run. haha

 

I would spray some carb choke cleaner around some vacuum lines. But it is essential that the engine is cold. So let it cool down for an hour or two. The colder the safer it is.

http://www.youtube.com/watch?v=9CPqbaSgcok

this video will help a lot.

 

Thanks, that video helps a lot. My bmw has a vacuum leak too, so I'll get some use out of that technique! I've been busy and havent been able to try it out yet though. I'll let you all know once I get a chance to work on it some more.

 

i played with the idle screw and the idle dropped to 2000rpms, so it's better but still idles high obviously. I just need a tire and to get the battery charged and it will be good to go.

 

with that high of an idle it will burn a lot of fuel.

 

hey man you wanna check your fast idle. take it off and take off the end cap and screw the plastic piece down all the way and back it out a quarter turn. and see if that helps. i had a real bad idle problem on my crx and it was me iacv, fast idle, and idle screw.

 

Was there no vacuum leaks? Seems like a dodgy solution to the problem.

 

im going to vote your fast idle thermo valve (stated above) needs checked and probably just screwed back in. also, you cannot properly adjust your idle by simple twisting that screw. the service manual says you need to unplug the iacv, set idle to proper rpm via the screw, plug the iacv back in and reset the ecu. i would check the FITV and adjust your idle correctly. ignition timing will also play a roll in proper idle speed.

does engine temp effect the idle speed at all? meaning is it only reving high when cold or at all times?? these things will help to diagnose this too.


good luck

 

Thanks for all the information guys, I'll probably get back into it later this week to figure out the root cause and get her running right. I'll hit back when I have more info. I was just excited to be able to drive her around the neighborhood! haha. Thanks for the help

PS here is the car as it was sitting yesterday.