With such a high idle, I would first suspect a vacuum leak or a stuck Idle Air Control Valve. Check your vacuum hoses and tubes (and the flame trap tubing) for breaks or disconnected lines. Remove the large accordian tube that runs from the Air Mass Meter to the Throttle Body and inspect it for hairline cracks or splits. Remove and clean your 016 Idle Air Control Valve (spring loaded). Note, the 016 has a rest position that is partially open to allow a specified amount of air to pass (since there is no Idle Adjustment Screw on the LH 2.4 vehicles).

If you replace your spark plugs, the new ones should come pre-gapped and will not need adjustment. I would definately advise changing the air filter, and also checking the condition of the Air Box Thermostat (it's below the air filter, selects cold air intake or pre-heated air intake depending on ambient air temperature). If the Air Box Thermostat fails, it defaults to the pre-heat position and draws hot air off the exhaust manifold and will quickly kill the Air Mass Meter.

God bless,
Fitz Fitzgerald.
--
'87 Blue 240 Wagon, 254k miles.
'88 Black 780, PRV-6, 146k miles.

Remove the throttle body and clean it throughly w/ some spray brake cleaner and and old toothbrush. Remove the air bypass valve under the intake manifold and clean the valve, again with brake cleaner. Keep spraying until the valve is free and flops around when you shake the valve. Check all vacuum hoses for leaks.

Hi,
I had a similar problem with my 89 740 (which is now dead due to a horrible crash - but it saved my arse!)
The things I did:
1. cleaned the flame trap
2. disconnected and cleaned the terminals and hoses for the idle air control valve.

You'll find amazing instructions within the 700/900 FAQ in the Features section.

: )

John