Mitsubishi Repair: 3.0 mitchubishi 1994 timing, auto parts stores, time george

Question
year 1994
model caravan
engine 3.0 v6

There are three groove marks on my crankshaft pully.  I want to time the engine to 12 degrees.  Which groove do I use?  Why are there three grooves?  I guessed the first groove means before top center, second groove means at top dead center, and perhaps the third mean after top dead center?

thanks for your help and time
george

Answer
George,
I'm not too familiar with the Mitsu engine that was put in the Caravans.  But yes, the markings I believe you are seeing are the degrees you can set the timing to.  The marking to the far right is typically TDC, then 5 degrees BTDC, then 10 dgrees BTDC.  Most engines do not want you to set the timing after TDC.  But because the timing is regulated by the car's computer, you'd have the ground the ignition timing wire on the ECU in order to properly adjust the timing.  You should pick yourself up a Haynes or Chiltons service manual, and that will have procedures in it to walk you through setting your timing.  Visit or call your local auto parts stores to see if they carry a service manual for your year and model of minivan.
Good luck!