Ignition Timing

[Leeroy94]

My timing is out on my rb20det so I read up on all these forums and eventually found a PDF manual on rb engines.

In the PDF it says the first step is to change the idle speed to 650rpm.

Engine was originally idling at 950rpm

I unplugged the AAC valve plug (brown) and it dropped to 650rpm for about 3 seconds. Then it slowly dropped over the next 10 seconds until it stalled. I tried adjusting the idle screw both with the AAC valve plug hooked up and disconnected. No change in RPM.

Another forum suggested to disconnect the TPS (rb25) but for rb20 it is not necessary.

I'm really stumped..

[89CAL]

You might need to wind the idle screw all the way in or out (sorry having a mental blank as to which allows more air through)

But raise the idle as much as you can first then work backwards

Keep in mind there are 2 plugs on the AAC unit, I don't remember which one you unplug to do this