Hi

 

when I remove the IAA (Air Idle Control Valve)connector and measure the resistance across the "poles" of the IAA unit,

should there be a steady resistance there, and if so, what should the resistance be?

 

:o)

 

Maz

I found this link a great help mate. Worth a read.

 

http://www.pexcom.com.au/z32cms/e107_plugins/content/content.php?content.335

Nice one mate

 

Cheers for that :)

No problem mate.

 

I have been servicing and setting mine over the last few weeks. (all 3 valves relating to the idle system) I have finally got her to settle at a smooth 750rpm at full operating temperature.

 

What sort of issues are you having?

I have a high idle, around 1300 - 2000 rpm. have checked most things and the IAA unit was Kind of the last Thing after eliminating the other possibilities.

I just cleaned the connector to the IAA and measuresd the resistance across the poles and it´s all over the place, from 0 Ohm to 24 ohm and constantly changing, which leads me to believe the IAA unit is shot.

okay

 

I cleaned the IAA connector and now have about 10 ohms of resitance as specified.

 

I let the engine run and warm up , it idles at about 1500 when cold and Drops to around 1100-1200 on idle when warm. Looks like White smoke from the exhaust and smells like fuel. No noticeable power loss either.

have you checked the ecu temp sender unit?

When you are at full temperature, try disconnecting the IAA connector. (it's the yellow one on mine) Does the idle drop then?

If it does, what does it drop to?

As Medallion Man says, worth checking the temp sender.

also have a look here:

 

http://stadzport.com/FSM/EFEC_Engine_Fuel_Emissions_Control.pdf

 

page 69 .. might help..

yes I have mate. Did an ECU fault code check, checked the ECU temp Sender, TPS , Throttle boddies, No boost leaks (anymore) either .

 

When I disconnect the IAA connector there is no Change, not even a slight drop, no difference between connected and disconnected .

Could be that your base idle is set too high?

Try disconecting the IAA connector again and adjust your base idle via the adjustment screw.

Clockwise should bring the idle down. Count the number of turns you make, as you may want to revert back if this makes no difference.

Could be that your base idle is set too high?

Try disconecting the IAA connector again and adjust your base idle via the adjustment screw.

Clockwise should bring the idle down. Count the number of turns you make, as you may want to revert back if this makes no difference.

 

See mate, after all the grief you had with yours you now know the IAA/IACV setup inside out :thumbup1:

redwine

 

I did the base idle Thing, this brought the idle down from 1500-1600 rpm to 1100 - 1200 rpm, the screw won´t go in any further.

Did you say that you have checked you TPS?

Voltage should read around .42 volts and should gradually increase as you operate the throttle. If this is incorrect it can also cause a high idle.

That is one Thing I haven´t checked yet. Not sure how that could have changed after a 200km trip all of a sudden, but you are right, I

Need to check the voltage on the TPS still .

That is one Thing I haven´t checked yet. Not sure how that could have changed after a 200km trip all of a sudden, but you are right, I

Need to check the voltage on the TPS still .

 

I see, wasn't to sure of the circumstances as to when the problem occurred.

As you say though, still worth checking if only to eliminate it.

Have you also checked the connection at the auxiliary air control valve? maybe worth checking the resistance to that also.

It has an integral heater that may have failed causing the idle to stay high.

 

http://www.pexcom.com.au/z32cms/e107_plugins/content/content.php?content.335

Edited April 27, 201312 yr by redwine300

redwine

 

which connector are you refering to, the connector on the "side" of the IAA ? i.e the one you would have to pull out "sideways" as opposed to "up"

like the yellow connector ?

I was referring to the yellow connector, the one you would disconnect up wards.

This is responsible for the ECU controlling the the idle just above base idle.

The connector that you remove sideways is for the F.I.C.D valve, this valve is responsible for maintaining idle when the engine is under additional load.

For example, when you activate the air conditioning or when the power steering kicks in.

 

The next unit along is for the axillary air valve, this is for aiding start up From cold. It allows a small amount of air in so as to raise the idle for a few minutes from a cold start. You can check the resistance for this which if memory serves me right should be around 75 ohms.

Also, when the engine is running, you should find 14 volts at the connector.

Edited April 27, 201312 yr by redwine300

Thanks for the excellent description of what the individual parts actually do mate , very helpful indeed

 

I will take a look at the Auxillary air valve and check the resistance, I´m guessing I might Need to remove and clean / replace the

IAA unit.

 

Thanks for the help :)

See mate, after all the grief you had with yours you now know the IAA/IACV setup inside out :thumbup1:

 

Thanks Steams.:thumbup1:

 

It's all down to your advice along with others, that has helped me understand some of the issues that beset these zeds.

 

It is a good feeling to be in a position to then hopefully help others.

Thanks for the excellent description of what the individual parts actually do mate , very helpful indeed

 

I will take a look at the Auxiliary air valve and check the resistance, I´m guessing I might Need to remove and clean / replace the

IAA unit.

 

Thanks for the help :)

 

No problem Maz, Glad to be of help mate.

 

As for cleaning the IAA, I would highly recommend it.

I have just cleaned and rebuilt both of the units involved on mine. A bit difficult to get to, and I would recommend new gaskets also.

Cheers mate

 

"New gaskets" plural ?, as in there´s more than just the main IAA Gasket i´ll Need ?

Cheers mate

 

"New gaskets" plural ?, as in there´s more than just the main IAA Gasket i´ll Need ?

 

Technically, there are 2 gaskets. One that goes between the AAI device and the plenum, the other one I refer too is the gasket within the Air control valve assembly.

Maybe worth leaving this one alone for the time being as I have not yet been able to source a replacement. I made one up from 1mm gasket paper.

Have you managed to check the resistance on this one yet? it may be that instead of cleaning it, it may need replacing.

Ah, okay..I´ll leave that one alone then

 

I did check the resistance and at first the readings were all over the place , not suprisingly though as the contacts were completely

oxidized. Cleaned them up and got a steady ready of around 10 ohm. Probably do Need to take a closer look / replace the IAA valve

as I had an issue with it before taking a while to drop to 750 RPM when stopping at traffic lights etc.

Hi Maz, I think I may have confused things here. I have referred to the Air Regulator valve as the Air Control Valve.

I would like to know if the air regulator valve is working correctly first of all. Please refer to the link in my initial reply.

This valve needs to have a resistance of 75 ohms and of course have a good connection. This is where you need to measure 14 volts at the harness connector when the engine is running.

If we can eliminate this valve, we will be able to concentrate on the IAA valve from there on.

Understood mate :)

 

Will take a look as soon as possible. Injured my Hand this morning taking a boat off a Trailer and puting it into the water.

As soon as I can move my thumb properly again (probably wednesday when I have a day off work) I´ll check the Air Regulator valve and get back to you.

 

Thanks for the help , much appreciated