Tom Mahan

I am trying to check the timing on my 81 gsl and it says to hook up the light to the following on the front of the engine. If you are standing on the drivers side of the car looking down at the plugs what 2 are following and what two are leading? also front engine bay? The one closest to the radiator? Thanks.
-Tom

LongDuck

Well, you're trying to time Leading and Trailing ignition, so you're going to time off of T1 and L1 - the front and #1 rotor and chamber.

Take the timing light and connect the lead to the L1 coming off the distributor cap to the L1 spark plug. BTW, the Leading plugs are on the bottom, the Trailing are on the top of side of the engine. ASCII drawing here:

___________
(( || || ||
((_|| T1 || T2 ||_______
))=|| L1 || L2 ||_______
)) || || ||

fan block tranny

This will give you the timing on the primary firing plug - Leading. As the rotor turns, the Trailing ignition (on top) will fire to ensure complete ignition. Leading advance is controlled by vacuum, with Trailing advance controlled mechanically to follow.

You'll need to look up specifics for where your car is timed by degrees ATDC and BTDC, but Mazda has made this simple by putting a yellow mark on your eccentric shaft pulley for Leading, and red mark for Trailing. These should be dead-on for correct timing, respectively. HTH,