[wounded horse]

My recently sold 2.0i 1994 had an idle control valve underneath the 2 part manifold which, when cleaned, made the car run so much better it felt like a different car. Does my recently acquired 2.0LPT 1993 - non intercooler ( but one retro fitted) have one? Can't see one but there is a slight holding back on acceleration and would like to do the valve clean and refit seeing how it cost me the price of a can of carb cleaner.

 

[Paul D]

If installed it will be in same location as your 1994 car. Silver tube looking like old type HT coil in terms of aluminium body shape/size - mounted on front side of throttle body. You can't miss it if it's there!

The ICV is not fitted to models which do not have the boost pressure bypass switch fitted (3 pipes to sensor mounted on r/h/s of radiator).

HTH's

 

[johncc]

That's interesting. I assumed all cars would have one. How is the idle speed controlled on those cars?

 

[StephenA]

And its not there on my MY92 2.3FPT but I do have the boost pressure bypass switch

 

[billj]

Originally posted by Paul D:
[qb]The ICV is not fitted to models which do not have the boost pressure bypass switch fitted (3 pipes to sensor mounted on r/h/s of radiator).[/qb][/b]

As far as I know non-TCS 9000s have an idle control valve, although its position varies. I believe cars equipped with TCS control idle using the electronic throttle so a separate valve is not required.

Certainly, my CSE auto 2.0LPT has no boost pressure control valve but does have an idle control valve tucked between the throttle body and cylinder head (where I believe it is to be found on all Trionic models).

 

[Paul D]

Maybe I'm going to have to eat my hat but I was certain my 1998 2L Anniversary had no ICV, although it has one of the later Trionic systems.

It doesn't have an electronic throttle, for sure.
I must check out which versions of trionic were fitted per year.

I am led to believe idle speed/tickover without the ICV is managed directly by the ECU.

 

[billj]

There were two versions of Trionic 5 fitted to the 9000. The 1993 Aero got the original version, then all turbo models got the newer version of Trionic from MY 1994.

Unless you look hard for the valve on your '98, you won't see it as it's tucked away under some hoses. Your're right - I don't think any '98 models were fitted with TCS, and I'm pretty sure no 2.0 versions ever had it.

If the ECU controls the idle speed directly, how does it do it without some sort of valve or electronic throttle?

 

[Paul D]

Ah.. so my 1998 Anniversary must be Trionic 5 - thanks for confirming.

And following a rather contorted investigation, I found my ICV (1/2 size of earlier versions fitted on my 1993 9000), hidden under inlet manifold... so must remeber to eat my hat and thanks for the enlightenment!

I'd always wondered what new fangled method Saab had deployed to manage tickover!!