i STILL have a idle problem with my jdm obdII b18c in my 97 civic hatch. not throwing any codes. doesn't idle down when warmed up, when i restart the car it does. when rolling ONLY, the idle jumps to three thousand or higher, then doesn't come down until i come to a complete stop. this results in a non-existant deceleration. this really bothers me. once in a while, when i'm in second gear and coasting, there is a deceleration "blip" and when it does this, the headlights get bright, then dim when the deceleration stops. tried three different iacv's, still did the same thing. here's the weird thing, when i unplug my vss, the problem goes away, of course my speedo and vtec resultingly don't work. i tried three different vss's and still did the same thing. what is the deal here, no one seems to be able to give me any ideas. and before you tell me to check my fitv, i don't have one, it's obdII. please, please help.

 

bump

 

Idle Air Control Valve

 

**** i have the same problem... but everyone saying its vac. leak... but yeah i clean out my iacv... still doess it..... but mine is on 1500-1000... wierd ****... and i aint throwin out any codes...... but mine is lsvtec....

 

i don't know if anyone actually reads my first post, i have tried three different iac's, all of which work fine on my friend's cars, and none of them fixed the problem.

so m2slsvtec, are you really experiencing the same problem; what do you mean your's is from 1500-1000?

 

Is there any voltage problems with your alternator, I ask that because you say your headlights get brighter then dimmer. If not then it could be something as stupid as you throttle cable needing to be adjusted, it may just be to tight just loosen it alittle so it has some slack in it.

 

actually, the throttle cable has few mm more slack than what honda specifies.
i had already checked the charging voltage on my alternator, it's 14.3. thanks for the reply.

 

And your throttle body isn't sticking?

 

throttle body is not sticking. it doesn't act like it's sticking, if i'm on a slope and the car is idling, then i release the brake and start to roll, the rpm jumps up and doesn't come down till i stop.

 

your brake booster sounds like it is leaking and causing A vacuum leak, try unhooking the line to the brake booster and pluging it so you don't have a vacuum leak and drive it with just manual brakes and see if that makes A differents.

 

ok. i'll try that. thanks a lot for the idea. i'll let you know what happens.

 

well, i tried plugging the nipple for the brake booster, didn't fix anything.
any other ideas?

 

It was the wiring on the MAP sensor this whole time and he fixed it tonight. 2 of the wires were crossed.