LT1,no vaccum comeing from unhooking the pcv valve,,get no suction into the intake,,,heard through other websites the IAC valve may have gone bad?yes or no.
never ever had any problems with my ride until i put some stp fuel cleaner in my ride 2 weeks ago,,having misfires and backfireing now,,,so sitting over time could the iac valve go bad since it is from 1993...go bad ?