Gas + oil

mrnickleye · 03-14-2007, 04:24 AM

I know the knock sensor, when working normally, will not allow timing advance if it picks up a pre-detonation of fuel, which causes a 'pinging'. I don't believe it will 'retard' the timing lower than the initial setting, factory 10*, others, like myself, 15*.

I believe I read a thread along time ago, here or on SM, that the computer richens the mixture. There was an argument, but I don't think it was ever confirmed.

Perhaps tomorrow I will put my car on the dyno, and smog machine, and pull the wire off the knock sensor and see if the mixture changes (by much).

But certainly driving the car with the timing not advancing as it should will cause bad fuel economy.

03-14-2007, 04:24 AM	#7
mrnickleye 1000whp postwhore Join Date: Jun 2005 Location: Mojave Desert, Calif. Posts: 1,705	I know the knock sensor, when working normally, will not allow timing advance if it picks up a pre-detonation of fuel, which causes a 'pinging'. I don't believe it will 'retard' the timing lower than the initial setting, factory 10, others, like myself, 15. I believe I read a thread along time ago, here or on SM, that the computer richens the mixture. There was an argument, but I don't think it was ever confirmed. Perhaps tomorrow I will put my car on the dyno, and smog machine, and pull the wire off the knock sensor and see if the mixture changes (by much). But certainly driving the car with the timing not advancing as it should will cause bad fuel economy. __________________ Had a Red 1989 N/A. Automatic. Sports Pkg. w/wing. TEMS, and some nice MODS. Sold to a friend 10/08/08.