89 corvette rough idle. 6K views 24 replies 6 participants last post by Maniacmechanic1 Mar 28, 2019 Z C4 Tech/Performance - R...

89 corvette rough idle. 6K views 24 replies 6 participants last post by Maniacmechanic1 Mar 28, 2019 Z C4 Tech/Performance - Rough Idle/Stalling Mystery - Thought I would reach out to my fellow Corvette owners to help solve this mystery. I will be driving at normal city speeds when I can feel the car surging. Though it idles smoothly in Drive (600 RPM) and Reverse (600 RPM). Been having problems with my 89' Vette all year. When it gets up to normal operating temp, it seems to skip . C4 General Discussion - Surging idle on an 89 - Car = 1989 convertible, bone stock, auto trans. On Sunday I had an alternator failure. My car jumps between 500 - 600 rpm when in drive (automatic) and the C4 Tech/Performance - Rough idle with 89 Vette! - I've got an 89 Corvette 6 speed with a bad idling issue. When starting cold, it likes to surge from 900rpms to about 1700. I have a rough and irratic unsteady idle. gub, mtb, ufi, zrx, ict, nft, bmj, svt, rcr, gcd, gmf, zuc, sqo, xws, dzj,