You can't properly set timing on these unless you disable the ESC (Electronic Spark Control). The ESC wire is in the center console, typically under the removeable tray in the front. It's the only single wire in there with an inline connector.

Once you disable the ESC by disconnecting this wire from itself, you'll get a Check Engine lite and the ECM will throw a trouble code for ESC. No worry, when you're done you reconnect the wire and the trouble lite will go away. The code will reside in the ECM for a certain amount of restarts until it clears out.

With the wire unplugged, set max spark advance to around 13 deg BTDC. This'll give the motor a bit more response than the stock setting of 10 deg BTDC. If you find you get more than a trace amount of pinging at 13, dial it back a bit.

Note: adjusting timing by ear on vehicles with an electronic spark control circuit is almost useless. You can't even tell what the timing setting is on a Trooper with 60 deg V6 unless you disable ESC.

I expect you'll find she runs much better after making the adjustment!

HTH............ed <img src="/forums/images/graemlins/kewl.gif" alt="" />