IAC issue VX II V6 3.8

[Nut Kracker]

Those instruction are from the Holden Factory Service Manual.
VT, VX 3.8L doesn't matter.....
Reset procedure for the GEN III is the same, but the 5 Litre is different.

 

[devilly]

From memory, you need to rev the car at around 2-2500rpm for 20 seconds or something like that, when you first change it over.
Plus there are two types of IAC valves, one is longer than the other.

yes this works awesome,because it's just a stepper motor controlled by the ecu

 

[kais3r]

Yeah I did 20 sec at 2500RPM which didn't seem to alter the startup RPM, but the settled idle revs were good from the get go without that procedure anyway.

 

[billythakid]

What is each one designed for, Different models? Do you know which each is meant for?

I've noticed some VT-VX have a machined groove on the Throttle body and a o ring between plenum and TB and others have a paper gasket ?
Maybe the IAC are designed for which TB is on the car

My late 02 Vx2 has a paper gasket between TB and plenum ??

 

[kais3r]

Yeah have the paper gasket too.
I've assumed the issue with startup revs is actually normal so thanks for all advice and will leave it be.

 

[Pollushon]

Where did you get the unit from? Some steppers are stronger than others. I might be nostalgic but no IACV ever seemed to ever work as well as the original one in my experience.

 

[kais3r]

Holden doesn't supply them anymore apparently so had to get one from eBay.

As far as operating while driving it works just as good IMO, just the startup revs was a little odd, but might be normal.

 

[billythakid]

Probably due to being aftermarket it might take a sec longer to sync with the Ecu

 

[kais3r]

Perhaps, but if it's just a stepper motor there shouldn't really be any synching between the two, just direct control which I'd think was more likely, but maybe the motor is slower at reaching its designated position.

Don't really have much of a choice as Holden don't supply them anymore and it does the job and 1/7 the price.

 

[Nut Kracker]

.....just the startup revs was a little odd, but might be normal.

It's normal.....

My 5 litre revs to around 1700 rpm on start up. Bit annoying actually, with a loud exhaust.
Sometimes, people think I'm revving it on purpose to attract attention.

SEQUENTIAL FUEL INJECTION MODE
When the engine is first cranked over, all injectors will be energised simultaneously. After the engine has been started
and a good camshaft signal has been processed, the PCM will energise each individual injector in the normal firing
order. This mode of operation helps to stabilize idle, reduce emissions and reduce fluctuations in fuel pressure.