I'm currenly having a problem with my car 90 Honda Civic Si ..I was hoping you guys could help me out or better yet have the same problem and cure the problem. I start my car and it idles around 3500 RPM and once it heats up the idle goes up and down between 1500-2500 at full warm up.. I've tried everything by swapping parts from my friends car.. such as ECU, MAP sensor,Idle Control calve, EAVC, Throtle body w/ throtle sensor, temp control, Fuel injectors. When i floor the gas ..it drives ok.. just on idle I also check the vacuum lines..no luck.. PLS HELP!!

 

Might try bleeding your cooling system. Air well get trapped in there and cause an idle like you described.

 

I concur... I've recently determined that if the cooling system is at or near empty the idle will stay at a constant 1250 rpm or so, probably due to the fact the car doesn't have to drive the water pump, easing the load at idle.

 

i dont know if this is 100% true but my homie said that there was a recall on something to do with the ignitor or distributor or something for hondas of that time period...my 89 accord does it too...he also told me that the recall is only good up too 100k miles then the replacement comes outta ur own pocket...but im like F-it cuz i got a 108k on it when he told me...never really had any problems with it anyways...car died once long time ago tho when the rpms bounced to low ...ill ask him again to find out what exactly it is he told me...sorry for not having the details...

 

After speaking with a honda tech, he told me there is a ball that sits in a cradle so to speak and at an idle the vacumm hold the ball in the passage way and prevents air from enteringthe housing. over time the ball wears and dries and possibly cracks and the total seal weakens over time, most just compensate with the idle, low h20 and oil is also a valid explanation, on thing I have learned is never underestimate the head ache of a honda.

 

Also, Always rememberthat with out a doubt, that if you, at any point if have a crack in a vaccum line that will always prevent a idle. Which explains the alright driving but no idle. Its not to expensive, try replacing all your hosing

 

i have an easy way to check to see if it a vaccum leak , start the car and let it warm up as normal , then pull a vaccum hose off , and plug it with your finger , it should idle like normal if the hose in question is leaking , has worked for me for a while. HTH

 

would anything happen if you pull the hose while the motor is running? also how do you bleed the coolant? i too am having this very very annoying problem. thanks

 

Your engine will try to die at first, then idle back up if you have your idle set properly.

To bleed your the cooling system - While the engine is cold, pull the radiator cap. Start it, and let it idle. There is a bleed valve on the metal fitting that connects to the head, and the top radiator hose attaches to. Just crack it open a tiny bit. As the engine warms up, and the thermastat opens you should start seeing bubbles of air start appearing, from the bleed valve and out the filler hole on the rad. Give it time, and let the cooling fan(s) come on. It may want ot drool, so put something down to catch it. Keep your face, and other body parts away from the openings, in case it tries to puke on you.

 

how much is a little bit? half a turn? thanks again

 

That sounds like a good start. If to much coolant starts leaking out, turn it back in a little bit.

 

Also, have you tried re-setting your idle following the described steps of unhooking your EACV ect..., after it has warmed up? Try unplugging it, and see what happens. You will throw a code tho so just ignore it. Just re-set you ECU after you have killed the engine and plugged the connector back on the EACV. Seems to me it's idleing a little fast for cold, mine starta out at, or around 2500. OOOPPPPSSS make that around 1700.


[Modified by 88_SC_CRX_Si, 7:45 PM 9/15/2001]