Erratic idle fixed ! Quick & cheap too. DeOxit D5 spray contact cleaner, toothbrush-sized S/S brush, a cut down emery board, and dielectric grease were used to clean some corrosion from the TPS idle switch connector contacts. Ops check good. It was immediately apparent that simply a thorough cleaning of the hard idle switch connector contacts gave a good result. Idle speed returned to 750 rpm without any hanging at 1500 ~ 1800 rpm. Afterward did the same to the TPS (actual) connector contacts for good measure. After that, performed voltage & resistance tests on the hard idle switch & TPS, both within limits. Passed my CA smog inspection the next day with pretty good numbers. Checking for corroded contacts should've been near the top of my T/S checklist. I 've been dealing with it on my 1991 Z32 NA since 1995. Live & learn (again).
