Typical Rb20det Idle Issues But With A Twist!

[Fernkeeper]

Hey guys and girls,

I've been having issues with my R32 RB20DET idling high at about 1100 - 1500.

Car runs fine just idles high. I have done some research and noticed this is a common problem and is usually fixed by cleaning the aac or replacing it.

I have changed the aac twice with both times cleaning them. No fix.

I have tried fiddling with the idle screw. No fix.

I have checked for air leaks. No finds.

I have changed the cold air regulator. No fix.

Note: When idling if I disconnect the aac plug the car just dies.

Any help would be appreciated.

[ErOR]

ECU temp sensor stuffed? How does the car run, is it running rich?

TPS set correctly (0.44v at closed throttle)?

Which AAC plug are you talking about, the plug going into the valve should not make the engine stall. On a 25de to set idle speed, I have to disconnect the brown (valve) plug.

A small leak is all it takes...

[Fernkeeper]

ECU temp sensor stuffed? How does the car run, is it running rich?

TPS set correctly (0.44v at closed throttle)?

Which AAC plug are you talking about, the plug going into the valve should not make the engine stall. On a 25de to set idle speed, I have to disconnect the brown (valve) plug.

A small leak is all it takes...

Now you mention it, it's running really rich. Car runs good but rich. How does the ecu temp sensor affect that? And where is it?

Tps is set correc.

when I disconnect the brown plug on the aac it dies.

[blind_elk]

The TPS has 2 components - a SENSOR and a SWITCH. The switch tells the ECU that the throttle is closed, and it is for situations like when the throttle closes during (manual) gear changes.

If the switch is not set correctly, then it can cause the ECU to maintain a high idle speed because it thinks the throttle is open.

Resistance between pins 1 & 2 on the TPS should be 0 ohms at "throttle closed".

[xntrq]

If you're in Sydney, PM me and I can run a scanner tool to diagnose your issue.

[IM-32-FK]

This might sound like common sense, but have you tried moving the tps? how you tilt it a bit and notice your rev's change? i had the same problem with mine for a while and i just kept tilting the tps and playing with that little screw valve on top of it and it eventually got it to sit on 900

Edited April 17, 2015 by IM-32-FK

[89CAL]

The TPS has 2 components - a SENSOR and a SWITCH. The switch tells the ECU that the throttle is closed, and it is for situations like when the throttle closes during (manual) gear changes.

If the switch is not set correctly, then it can cause the ECU to maintain a high idle speed because it thinks the throttle is open.

Resistance between pins 1 & 2 on the TPS should be 0 ohms at "throttle closed".

Mostly correct but it wont show 0 ohms at closed throttle. Probably be 12 ohms or so. Sensors usually work between .5v and 4.5v and anything outside that is out of range. This is how computers work out something is wrong with the sensor. 0 ohms is considered to low resistance and will log something like sensor voltage high etc

Not trying to be critical of your post. Just adding something