Idle Air Control Valve / supposed to have constant signal??
 

I have a 2001 GSR and I am having major idle problems. All vacuum hoses are 100% correctly connected. When I hit the throttle the engine wants to die.

IS the ECU supposed to send a continuous signal to the IACV? When is the IACV supposed to receive a signal.

Re: Idle Air Control Valve / supposed to have constant signal??
 

Cold start and anytime a load is placed on the engine, there will be a command from the ECU to maintain correct idle speed.

Re: Idle Air Control Valve / supposed to have constant signal??
 

I too am having idle issues. My idle bounces. I already cleaned my iacv, but wou
D replacing help better.

Re: Idle Air Control Valve / supposed to have constant signal??
 

is this an all-stock car? as in, a 2001 gsr with the original motor?

and no, the iacv runs off a pulse-width-modulated signal. (think fuel injector.)

Re: Idle Air Control Valve / supposed to have constant signal??
 

Your wrong


The iacv has a constant 12v and a pulsed negative path.
Cold starts and based off the eld and a/c.

Op set your base idle and go from there.

Unplug your iacv set your idle screw to idle at 650rpm then reconnect your iacv and reset your ecu.

If the problem persist check for 12v at the yellow/blk wire.

Does your idle surge??

Have you checked your fuel pressure?

Have you checked your fuel filter?

Any resitrictions in the intake?

Re: Idle Air Control Valve / supposed to have constant signal??
 

When i find these weird idle problems I almost always find a vacuum leak or a fuel problem. Spray brake cleaner where the intake manifold gasket is at and where the throttle body gasket is at.

Re: Idle Air Control Valve / supposed to have constant signal??
 

Don't mess with the throttle body set screw. That's not idle screw. It will, but it isn't supposed to be changed to adjust idle.

IACV is always getting signal when you're at idle. It's a secondary throttle valve that is electronically modulated by the ECU to coordinate air input with fuel input.

pulsed positive/negative is not relevant. It is pulse width modulation either way contrary to what turbohatch96y7 else said.

Fuel filter is almost never an issue at idle. A restriction there will cause issues by dropping fuel pressure when you try to draw a large amount of fuel like climbing up a hill or accelerating.

Vacuum leak is a good possibility just like miklo said. That and emission controls like PCV and EGR.

Re: Idle Air Control Valve / supposed to have constant signal??
 

Who is this guy^^

It is relevant wich side is pulsed to do test's and record data. To get to the root of the problem.

Nobody ever said anything about the throttle plate stop screw.



Op to check for a vacume leak cover the throttle body inlet and starve the engine of air if there is a leak you will here a pronounced noise as the engine gets air from your leak.

Re: Idle Air Control Valve / supposed to have constant signal??
 

A tech who can spell and write better than you.

Someone said it is PWM which I agree. You discredited him and said its wrong, then inferred that negative pulse isn't PWM.

Idle speed is not set on OBD II cars with adjustment screws typically. What exactly did you mean by "idle screw" ?


You sound like a shade tree mechanic. How exactly does that help identify leak downstream of throttle body?

Your method is inferior to using the flammable gas method. Flammable gas method works because when fuel vapor enters the engine through the leak it alters the A/F ratio and affects idle.

Re: Idle Air Control Valve / supposed to have constant signal??
 

Ouch!


I grew weary of arguing with him....

Re: Idle Air Control Valve / supposed to have constant signal??
 

Most of my post are from my phone so if you can't get yourself to read simple english I'm sorry for you and your children.

I'm not even going to argue the rest of your useless post but let me think for more than a second....... Spray flamable liquid on my HOT engine and risk the chance of a fire or take a second and cover the throttle body to find a vacume leak...... Hhhhhmmmmmmmm I wonder what I'm gonna do.

Re: Idle Air Control Valve / supposed to have constant signal??
 

And dcfiver I'm suprised your even in this thread there wasn't any talk about scan tools and lug nuts.




Ouch.



And I never argued with pwm. I simply stated there is a constant 12v positve on one side of the solenoid dick.

Re: Idle Air Control Valve / supposed to have constant signal??
 

Hahaha hack. Youre out of your league. Stick to the shade tree son....

Re: Idle Air Control Valve / supposed to have constant signal??
 

If you knew how to read an electrical schematic and not just a scan tool you wouldn't be such a tool.


And no where in my post did I say "no its not pwm" reading owns you.
Keep doing smog checks bro.

Re: Idle Air Control Valve / supposed to have constant signal??
 

What was the last thing that was done to the car prior to this problem, or what set it off. Where does you engine idle?


No IACV idle is 450rpm +/- 50rpm, meaning with no manifold leaks, and the PCV system working properly. If it is lower than this you must adjust the idle screw assuming no other problems. If your turning this screw more than a full turn in either direction you may have something else going on, some air bleeding from something.

Re: Idle Air Control Valve / supposed to have constant signal??
 

this thread made me rofl. i bet this guys still got a idle problem.

to the guy with the disgust in the flammable liquid technique, you're a moron. if you know how to use a scan tool, you would also love flammable liquid like... brake clean. ever seen brake clean ignite on a hot engine? i don't think you even know your asshole from your elbow bro.

connect scan tool, watch o2 input and a/f. when it goes rich you found your leak. simple shit right there man.

now to thread jack!

my buddy did a ls/vtec obd1 swap in a obd2b car and its idle surges. there are two identical connectors one is PS Pressure Switch one is IACV. how do you tell which is which? regardless it idles just fine with the IACV disconnected. how ever his pcv valve is missing from the black box and the vacuum port is capped off (i know not advisable but he's a broke sob).

/threadjack

Re: Idle Air Control Valve / supposed to have constant signal??
 

I have. Twice in 15 years. Brake cleaner is extremely flammable. And advising someone to spray a flammable liquid around a hot engine is foolish. Controlled propane is a much safer option.

Re: Idle Air Control Valve / supposed to have constant signal??
 

have you done anything with the TPS sensor? I know if the wires are backwards it will sometimes do this.