Hello,

Having an 82 like yours, do the RPM's go up when the AC switch is just turned on but compressor is not running (not needed yet). It should idle at about 800 rpm's like this and then go up about 850-900 when the compressor cycles. If it does not check, the micro switch on the ac temp control it might have broken off like mine did. This allows the rpms to go higher in preparation of compressor cycle. I found this out when my switch broke in the operated position and I could not get my idle down. I fixed it with crazy glue.

If this is not the issue, you could find the lead from the CIS/ECU to the engine temperature sensor and place a 1000 ohm variable resistor in series with the lead through a toggle switch. When you throw in that resistor the idle will go up to the RPMs desired as per the setting of the resistor and the switch. What you are doing is tricking the ECU into thinking it is a cold motor and it adjust the idle upward. It has no effect while running, only on idle. Have fun.

Mario
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82 242 DL-MPG