Owner of 2 RRC & 1 D1. Timing was jumping so installed new chain and sprocket gears. Improved but still jumps about 1/2 inch when timing lit. No codes. Idles 5 minutes and then a knocking appears and knocking volume increases. Vacuum test returns a steady 8 value. Driving round the block surges, stumbles, & shakes. Compression test returned all but 1 cylinder as strong so fitted new rings to complete bank. Pulled Dizzy and inspected - Spring loaded good and gear teeth good. Anyone been here before?