LS1-450

iTrader: (33)

Anyone experienced this? There is a tick & the fuel trims are adding fuel. There is unburnt fuel firing in the exhaust. Have checked rockers, pushrods, valve springs, valves. Rocker motion looks OK when turning engine over with the starter. Only thing remaining are the lifters. There is a lifter tick. Am not sure how a bad lifter or lifters woud cause the fuel trims to dump fuel due to a lean condition, but there is no other area to look to. Valve covers are not connected to the intake vacuum nor is the valley nipple.

Please comment, thanks.