1986 560 sl
 

failed smog way too rich.found spark plug crossthreaded fixed it.
idle air controller will actuate if jumped with 12v but system is only supllying 1.2 v at idle to it.
found injector o-rings leaking replaced all o-rings and sleeves.
when checking for vacuum leak i leaned out system and artificially enriched area around intake.got a huge jump in rpm at back of throttle body area.
took of fuel distributor air valve assy found no hoses leaking.
charged intake with smoke and had no leaks in itake area at all.
put it all back together and still get big hit with enrichment under intake.
also vehicle idles at 15 to 16oo rpm.

sounds like your idle control unit is bad.

Jonathan

the actaul idle air control motor works when actuated if there is a control unit for it where is that located?

560sl
 

the control unit is mounted behind glove box along with 20 of it's closest friends.

ok i checked idle air controller no voltage to motor circuit
i apllied voltage with controller still plugged in vehicle idled down to normal idle
8v at + terminal of motor
so is this a controller fault or maybe the controller isnt getting correct
input