ICV questions

[frankandbeans]

I am having idling issues, and I think its the ICV, i cleaned it out, but still pretty sure its something with the ICV.

When the car is on the on position, is it buzzzzzzzzing. I was wondering if this is normal.

[E30_fiend]

If its buzzing then its working.

What are some other symptoms you're having? Idle surge? Dying?







Taylor

[frankandbeans]

Car idles high almost constantly. Sits around 2k maybe a little higher or lower.

Randomly comes down to about 1200, but then will go back up and just sit there. No matter what, if i'm in gear it will want to push the car till it gets to 2k and then just sit there, or if I'm in neutral it will just sit at high idle, even when the car is warmed up.

Just changed the transmission, but I don't think that would effect my idling problem.

[frankandbeans]

Anybody??

[Fidhle007]

What happens when you unplug the ICV?

[E30nate]

my car is doing the same thing. i have tried three different icv's. also, when i cleaned them out, a shook them to get all the carb cleaner out, and noticed something loose inside. is this normal? when i unplug it, nothing happens, but sometimes the idle drops from about 2k to about 1.5k

if i find anything out i will post up to help out.

[EvoStevo]

Mine buzzes when the key is in the on position too. My idle is anywhere from 750-1100 rpm when I start up. Don't know if that helps.

[BobombETA]

Unplug your ICM and see if it makes a difference.

[E30nate]

so i was checking mine out again today. nothing changes at all when i unplug it. i swapped out two more known working icv's, and nothing. i was checking voltage at the connectors, and got some wierd readings. on one wire i got 12v, on the second i got 5v, and on the third i got 5v. shouldnt there be a soarce, signal, and ground, so the readings should be 12,5, and 0 right?

[drivnvordaedge]

check for vacuum leaks ..

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i am having the same problem with my m20 motor .... it is to the point where i cant pass emissions at idle...

i experienced a surging idle ... that would surge and calm down at 900 rpms after a couple minutes .....

they did a smoke test and found leaks coming from the tubing .. supposedly around the pcv

we also found that the throttle cable was tooooo tight .... it opened up the throttle plate making it come off of the idle circuit

so to test idle circuit.... when u manual move the throttle plate ... u should here a click as soon as you give any force ... like giving gas

it is a very soft click ... so make sure it is very quiet and put your ear to it...

so if the throttle plate has been adjusted to the point that it is so tight that the throttle plate is already opening and off that idle circuit .. it will send your computer wacko

also there was a carbon ring deposit in the throttle body that sometimes caused the throttle plate to stick ... making the throttle plate come off of the idle circuit (the click u were checking for) .. so the cars computer thinks you are giving gas ....

just saying something that have been happening to me

also check that that tube underneath the intake manifold that goes into the block/oil pan and has that spring ... see if at the bottom the rubber gasket thing on the bottom is ok ... those are prone to getting rock hard and cracking

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idk if this will help at all ... but its something i guess

[nando]

so i was checking mine out again today. nothing changes at all when i unplug it. i swapped out two more known working icv's, and nothing. i was checking voltage at the connectors, and got some wierd readings. on one wire i got 12v, on the second i got 5v, and on the third i got 5v. shouldnt there be a soarce, signal, and ground, so the readings should be 12,5, and 0 right?

it's a pulsed signal. You wouldn't be able to read a solid voltage on the signal wires. The 3 wire ICVs have 2 windings, one to open and one to close, so either of the signal wires could be 0v or have the pulsed signal depending on which way the ICV is moving (open or closed).

[E30nate]

so what does it mean if both signal wires have voltage at the same time?

[nando]

probably that it's not trying to move the valve in either direction, ie holding steady.

[E30nate]

i got 6 volts on both wires with three different valves at varything throttle positions. didnt change at all. all three valves buzz and everything.