I just changed my alternator in my 1990 na and my idle is a bit off, +/- 650 Rpm. Im tempted to adjust it via the idle adjust screw located on the throttle body but am hesitant cause im not sure whether it's safe to do so without grounding the initial set connector(green plugs near leading ignitor) or whether this is indeed the correct avenue to achieving a smooth 750 idle.
Thanks in advance, any help will be greatly appreciated.

Steve W.

oh yeah, Is it normal for the idle to drop 100 Rpms to about +/- 600 Rpms when the lights are turned on and Is an Alternator reading of 14.5 volts on a digital multimeter appropriate while the car is on w/out any elec. loads?

Thanks again,
Steve W.

 

Yes, you can adjust the idle without jumpering the initial set connector, but I do not believe that is the reason your idle is low. It sounds to me like you have accidentally disconnected and/or loosened the electrical connector on your BAC valve. If the connector is tight, you should jumper the initial set connector to ground and at idle, disconnect the BAC. If the engine RPM does not drop, it may be dirty and/or defective, or the ECU might be bad. The reason I say that the BAC is not functioning is that it is supposed to prevent idle drop when the load changes - that is, the lights are turned on, and it is not doing that. To correctly set idle, the BAC must be working, and the initial set connector must be jumpered. Hope this helps.

Irv, Keith's dad

PS your voltage at idle is excellent, your new alternator is lookin' good!