Erratic Idle - Changing Throttle Body / ICV

[rossyl]

Hi All.

I have the following issue with a MX5 mk1 1.8.

Occasionally the idle surges to above 1000 RPM, then drops and stalls. Or, very occasionally, drops pretty low for a shirt while before recovering.

It tends to happen when the car is hot, after a hard run, and is then sat idling and stationery.

Dipping the clutch makes no difference.

I tried a different MAF, initially this led to a higher idle speed, but now the same problem has returned.

I have been advised to change the throttle body and ICV. I've found this video:
https://www.youtube.com/watch?v=G7keMMthYrQ
https://www.youtube.com/watch?v=a0P2p8QMOIA

It looks manageable. However, will i not need to re-set the ICV screw?

Also - the gasket for the throttle body, what is this? In the first video they just use a paste, in the second an actual gasket.

Thanks

[rossyl]

The issue was actually the Clutch Switch. Which lets the ECU know that the car is in gear.