405 Idles too fast

PaulRoper

Member
Fellow Frogger
Joined
Jan 12, 2003
Messages
50
Location
Adelaide
Can anyone help with this annoying problem.
My Series 1 405 (1989) runs well, but I can't get it to idle slow enough.
The idle speed screw is all the way in!
There doesnt appear to be a manifold leak (not obvious if there is).
This symptom started suddenly.
I have temporarily blocked of and bypassed the Supp. Air device.
Now at least when cold it idles @ about 850- 900rpm, but when hot, idles @ around 1250-1300 rpm. Air Con slows it to about 1050rpm.
Could this be the Manifold Air Pressure sensor ? if so Where the #$%@ is it ? and how can I test/check it ?
Is there any way of testing the S.A.D. also ?
Any other suggestions ?
 
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