All of a sudden I am idling at 1300 rpm.
Checked all over for vacuum leaks and found none. I took the maf off and cleaned it lightly with either and it seemed to idle for about 10 seconds then back up?
What else can cause it?
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EDIT: On your 86.5 it is way easier to check the ISV than on an S4. Middle pin on the valve is 12v. Apply ground to each outer pin - one at a time - and you should hear the ISV move.
Last, on the S3 motors there is a shorty harness from the idle/wot switch to the main engine harness. It can also be a problem. Most original-equipment shorties are dead by now. The harness is NLA. You have to make a new one from new connectors. Or I think 928sRUs sells a pre-made replacement.
-- Dave C
Front-Engine: '94 928GTS 5sp (CarChick's); '91 928GT (Supercharged); '89 928GT
Mid-Engine: '14 981CS (CarChick's) A$$-Engine: '15 991TT
928 Owners Club Charter Member
Agree with Dave C., probably the harness for the idle/WOT switch. Mine disintegrated as most do. 928sRUs does sell a replacement since it is NLA from Porsche.
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