Check engine light came on intermittently actually just once.I pulled a code 42 this seems kind of hard to figure out.Today while the car was idling in park the motor increased in rpms and backed down after maybe 3 seconds?? My auto seems to kinda have a tuff time to turn over, 2 year old delsco battery and delco stater.The alternator checks out so I think it has something to do with the code 42 ANY HELP would be wonderful, and thanks in advance.The plugs, coil packs were replaced 18 months ago.

42 is a EST (electronic spark timing) failure code. Could be a sign of the ICM on its way out. For now, and since the car still runs, I would just clean, and re-grease the ICM base to ground, and any other electrical connections that look like they might need it. Especially on a 1990.

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92 Olds 98. L67, Gen 3 M62, 2.55 pulley, FWI, PLIM, 1.8 YTs.