So quick question because i have searched on these message boards and cannot seem to find the answer. Does anyone know what the correct spark advance is on a 91 z28 5.0 TPI motor? My current reading while idling is 18.2* @ 703 RPM. I really need help on this issue before I start doing any other sort of work on the car.

 

Follow the emissions stickers direction. It has the timing spec & procedure.

 

The timing spec for the lb9 is 6 degrees advanced with the est disconnected.
https://www.thirdgen.org/forums/tpi/...es-91-z28.html

 

thanks the owner prior to me removed the VECI label so I had no clue at all. Now that I know that it's way off I'm definitely gonna resolve that issue today. Thanks

 

np

 

Ok here's an update on the the vehicle. I adjusted the timing to 6* BDTC with the EST disconnected. I reconnected the EST and tightened everything else down. The car started up fine but when I went for a drive it started surging on me a bit and using my Autoxray diagnostic tool it was showing that the vehicle was knocking when I would start getting on the throttle. When the car idles it feels like it's gonna die. Any ideas?