I'd like to replace that terminal,,,,,if you find one please post a part number and where to get it. Mines repaired but I solder wires close to the plug and it probably going to vibrate and crack.
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On your 2,000 rpm after unplugging ICS. If you unplugged it when engine was cold it was unplugged in wide open cold position. Warm the engine up then unplug.
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A few years back I got newer used terminals off a Montero sport 3.0. TPS and ICS,,,cut long enough wire with them out of harness to solder in farther unpstream. I wish I could do that on the ICM but all the wires in the just yoard look just like mine on that terminal.

dave h.
'89 Raider V6 5spd;Aisin Hubs;; Gen2 LS: frt. brakes, rear coils;U.C.arms;R.trailing arms;idler arm; rear LSD axle w.disc brakes ;2 battery system for Dog's fan; relocated ECU; custom bumpers;J.Baker receiver;Conferr roofrack; t-bar crank.