Page 1 of 1
Re: Series 1 1990 2.0i XM Auto Throttle Body
Posted: Wed Jul 30, 2025 1:11 pm
by Tim Young
Pictures of my throttle body from above with views of throttle adjustment screw and idle control screw.
XM Throttle Body.jpg
Throttle Body
XM Throttle Screw.jpg
Throttle adjustment screw.
XM Idle Speed Screw.jpg
Idle speed screw.
Re: Re: Series 1 1990 2.0i XM Auto Throttle Body
Posted: Thu Jul 31, 2025 6:30 am
by Dieselman
Assuming this is connected to an idle speed issue, the lower screw is the throttle setting for idle speed and isn't the upper screw the stop for the secondary throttle flap, which should be closed until the main throttle flap is about 3/4 open.
That will then give the minimum volume of air the engine can be fed with and any additional air required for cold starting will be via the supplementary air valve.
The throttle switch needs to sense the throttle closed/open. It should click as the throttle is opened a little and closed.