vpforeva

Hey guys, i have a problem with my idle, mines a 92 Si. My idle of my car completely warmed up is about 500 rpm, it is supose to be 750 rpms right? and sometimes, mostly during hot days, when im coming to a stop and shift into neutral, my rpm would go down and drop past the idle goes to 0, and then bounce back up and down between 0 - 750. Sometimes the car would even stall. Does anyone have this problem with their engine and have fixed it? I talked to my mechanic and he said to replace the Air Idle Control or Idle Air Control or something like that i forgot, its in the throttle body. He said its around 100 dollars from the honda dealership. Does someone know the part im talking about and can give me an exact name, and any other thoughts on whats causing my rough idle. Thanks

vpforeva

bump

spangler

new injectors

vpforeva

if the injectors are bad, wouldnt my car run bad too? not just the idle? my car runs perfect except for the idle, come on guys anybody else can help me out here? so knowledgeable about jdm swaps, turbo and nitrous, yet this is just a simple problem

spangler

are right listen heer injectors are bad whenb you at idel there isnt as much pressue going to the injecters but when your running theres no problem cayuse there more presse which mean more fuel which mean no problem=im not ******* dumb i had the exact same problem in my lude went threw everything changes all four injectors bam smooth idel just try what can it hurt firts of all honda injectors are the shittest things made so your gonna benfit either way buy changing them...try and see and get back to me

vpforeva

k thanks, i never said ur dumb =]

H22TurboATR

It's called the IAS Idle Air Sensor.
You can also try opening the throttle body more. There is a screw that allows you to set up how high or low it idles. (it's also on the TB)

DirtyLude

It's not the injectors. I don't say this much, but the guy who offered that as a solution is a retard. BTW, the fpr is 1:1, meaning the pressure that's added to injectors when you open the throttle plate is offset by the pressure in the plenum, so pressure differential is always equal.

IACV Idle air control valve. It's a solenoid that is pulsed by the ECU to maintain and hold idle. It routes air around the throttle body. It's likely that's your problem.

Before replacing any parts, the proper check procedure is to look at your plugs to see if there's any indication of running too rich or lean, check your air filter to see if it's accessively clogged, and pull your PCV valve to see if it still flows. If nothing seems wrong, do the idle adjustment.

The proper idle adjustment should be done. Warm the car up, make sure all the accessories are off, and pull the plug from the IACV. Idle speed without the IACV plugged in should be 550 rpm + or - 50. If it's not, adjust it. Turn the car off, reconnect the IACV, and reset the ECU. Start the car and see if that corrected the problem.

It's a simple check that takes 15 minutes. If none of that works you can start checking ignition components.

vpforeva

hey dirtylude, i checked in my honda service manual, theres no iacv, theres only a fast idle valve and a electronic air control valve, so that would be the samething as iacv right? since in the service manual it tells me to disconnect the eacv and idle speed should be 550rpm or + - 50

well my mechanic told me that he see's for cars with idle problem, its usually the the fast idle valve, so i already bought it, i hope that is the problem =[, if not ill prolly have to shell out like 150 more for the damn eacv, but ill try your recommendations for the checks first

DirtyLude

It's extremely unlikely that it's the fast idle valve.

The fast idle valve is purely mechanical. There's a little wax pellet in there that when cold, lets air by, increasing idle. When it warms up it expands and closes off any extra air. I agree with your mechanic, these things usually go first, but what usually happens is the wax pellet doesn't expand enough and lets too much air by. This is when people start getting fast idles or bouncing idles. Yours is too low, which means you're not getting enough air. The Fast Idle Valve has no way of restricting any more air from getting in there.

A good article on Honda PGMFI idle air control. You should be able to diagnose your own problem from it. http://www.tech2tech.net/training/chpt_23.pdf

Good luck.


[Modified by DirtyLude, 6:20 AM 3/30/2002]

vpforeva

yea my idle does bounce, sometimes it goes all the way to 0 when i shift to neutral coming to a stop, and it would either bounce back up to 500 rpm or rarely it would stall, but when my idle is stable its usually at around 550 rpm on hot days or regular days, and when at night or something when its cold then the idle would be at normal specs, around 750 rpm - + 50. do you think its both the fast idle and the eacv?

DirtyLude

That's not really bouncing. If it was bouncing you would know it. It revs from 1000 to 1300 or so and bounces back and forth, not just once, it keeps jumping back and forth like that. It's usually caused by a vaccum leak, like from a fast idle valve.

The IACV is used to catch the rpms when you let off the gas. Everything your mentioning points to it. It's unusual for them to go out, though.

vpforeva

oh ok, thanks

i really hope its not the iacv, thats 150 bux =[