R32 With Rb25 High Idle

[Rob_C110GTR]

The car idles at 1120 rpm at cold start

When warm it sits on 1250 rpm

I've taken the aac valve and cleaned it.

The adjustment screw is all the way in. I can't find any air leaks. But the previous owner fitted a RB20 aac valve on the rb25det using a metal plate adaptor .

Next to check is the air regulator ? Which I've read is a pain in the ass to get to.

Any advice?

[blind_elk]

Make sure the throttle is closed properly and sending the "throttle closed" signal to the ECU.

[Rob_C110GTR]

Do the RB25 have the special coating in the throttle body like the GTRs? Or that's only on GTRs?

[Rob_C110GTR]

I've cleaned the air regulator the one under the plenum. Also cleaned the throttle body and made sure its fully closed at close position.

I've got a microtech dash and its displaying the tps at 0% on idle.

Cold start idles at 1120 rpm

Warms up it idles around 1250rpm

This driving me nuts

What else can I check ?

[Rob_C110GTR]

If I disconnect the brown plug for the AAC it idles down and can be set to the right idle speed. As soon as you plug it back idles back right up.

[blind_elk]

I've got a microtech dash

So are you running a Microtech ECU? Have you checked the target rpm @idle? Have you checked timing maps @idle? Have you checked fuel maps @idle?

[Rob_C110GTR]

It's running LT-8 but I don't have a cable and software to plug in to a laptop yet.

I've been researching and most threads point either to replacing AAC Or air regulator or cleaning which I've done.

But really wanting to replace the AAC valve as the previous owner installed a RB20 AAC valve and made a metal plate to fit on the rb25 plenum.

I can't find any info or instructions in regards to the Microtech Dash. Some forums states its only displaying data but microtech have them listed as displaying and also program the ecu. So not sure really as I've never played with these before.

Anyone got a diagram of how the hoses of AAC and air regulator should be connected?

[blind_elk]

Would have been nice to know from the beginning that you had an aftermarket ECU.

The Microtech will be programmed to aim for a particular rpm @idle. It will also have different fuel and ignition maps from a stock ECU. So the things that work for a stock ECU won't necessarily work for you.

I'm pretty sure it will be something in the programming of the Microtech that is causing this problem.

FYI - I run a Wolf on my RB25DET, and I have never had to adjust the AAC valve to set the idle. Idle is controlled by the settings in the Wolf, and it idles around 800.

[Rob_C110GTR]

Where's a good place to take my car get the idle sorted out in south side brissy.

I always pass Elite Automotive at Archerfield but I always see fords and holdens.

I've replaced the aac and recheck for leaks and I think blink_elk is right the microtech comp needs adjusting.

Anyone knows if its hard to do? if I buy the dongle as I can alway disconnect the microtech dash and plug it on to my laptop