| I have a 96 NA with 86k Miles that had been idling a little high around 900-1k RPM. I've set the TPS to .50 and confirmed the closed throttle position switch is ON via Conzult. New spark plugs, NGK PFR6G-11. 96 FSM says to check ignition timing with the TPS sensor unplugged and the idle around 650 +/- 50 RPM. When I unplugged the TPS sensor while in TPS adjust in Conzult the RPMs went up to 1200, dialed the idle down with the screw to 650 and the engine was lugging pretty bad, very shakey. Was able to confirm ignition timing w/ light at 10deg BTDC and Conzult showed 10deg as well, however the idle was fluctuating a few hundred RPM so the timing in Conzult was jumping around 1-10deg BTDC. Dialing the idle screw out to 900-1k RPM smooths out the shakeyness but there is still a small miss and the ignition timing in conzult goes crazy between 0-5deg BTDC. The timing light shows this as well. All injectors OHM at 11.9. All coil packs OHM at 1.0. Conzult reported a Code 71 however there is no MIL as the 96 FSM says there should be for that code (multiple cylinder misfire) Left bank O2 sensor at idle is reading high while the right bank is low. So I believe the core of the problem is indeed a misfire causing the rough/shakey idle. The fluctuating ignition timing at idle RPM I think points to that as well. How else do I figure out where the misfire is coming from? Also, why does the RPM rise while in Conzult TPS adjust then lower when that window is closed?
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