I know I'm not the first here but..... my beloved 1988 (20k) 328 throttle is starting to stick. I've cleaning the throttle plate and linkages at both ends and dripped 3-in-1 down the cable. No luck. It seems to get easier as the engine warms. I can't decide if the cable is fraying or whether it needs a better clean. Is there any difference to how these two feel when pressing the throttle? Any ideas? Should I give in and have it replaced?