High Tickover 1993 2.0 Turbo 940

[TonyS9]

1500 seems rather high to me for a cold start idle, seems more like limp mode or a falsely detected input. If there is no fault code then I think it can't be missing speed signal.

A few other ideas

-Coolant temperature sensor for the ECU, reading cold
-Automatic drive select signal - high
-AC on signal - high

All these drive the idle valve open as they use significant power from the engine. They should be grounded in a manual/non-AC vehicle.

[TonyS9]

Originally Posted by 360beast

Try all the positions, I found on the 1991 940 when I read the codes on, the engine slot didn't actually have a pin the other side and it was in another number.

I assume then nothing came out instead of 1-1-1?

[besidetheseaside]

Originally Posted by TonyS9

I assume then nothing came out instead of 1-1-1?

Yep just 1-1-1. Apologies for late reply, I have been chopping a cherry tree down

[besidetheseaside]

Originally Posted by TonyS9

1500 seems rather high to me for a cold start idle, seems more like limp mode or a falsely detected input. If there is no fault code then I think it can't be missing speed signal.

A few other ideas

-Coolant temperature sensor for the ECU, reading cold
-Automatic drive select signal - high
-AC on signal - high

All these drive the idle valve open as they use significant power from the engine. They should be grounded in a manual/non-AC vehicle.

1500 rpm is actually hot idle, cold idle is around 1000 rpm.
CTS is new. IAC shows as Ok on the self diagnosis test.

[besidetheseaside]

Thanks for the input guys, most appreciated. MOT is due in a matter of weeks so I need to sort it.

[360beast]

Originally Posted by TonyS9

I assume then nothing came out instead of 1-1-1?

Yep nothing as there was nothing for it to plug in to. When I found it in the other port it came out as 1 1 1.

[besidetheseaside]

Hope this comes out better Dave.

[Laird Scooby]

Originally Posted by TonyS9

1500 seems rather high to me for a cold start idle, seems more like limp mode or a falsely detected input. If there is no fault code then I think it can't be missing speed signal.

A few other ideas

-Coolant temperature sensor for the ECU, reading cold
-Automatic drive select signal - high
-AC on signal - high

All these drive the idle valve open as they use significant power from the engine. They should be grounded in a manual/non-AC vehicle.

It's mine that i've seen hit 1500rpm on a cold start Tony.

No linp mode or fault codes on mine either.

[Laird Scooby]

Originally Posted by besidetheseaside

Hope this comes out better Dave.

You didn't manage to turn it i hope Don?

[besidetheseaside]

Originally Posted by Laird Scooby

You didn't manage to turn it i hope Don?

Sure did, car was ticking over @ 1500 rpm, backed screw off and it made no difference so put it back where it was.