Ignition timing is not adjustable. It is determined by the crankshaft position sensor. The Engine Computer can't advance the timing because it can't get a pulse from the sensor, then fire a spark plug before that. Instead, there is a lot of advance built into the sensor by way of the holes in the flex plate. The computer gets a pulse, then waits a calculated amount of time before firing the coil. By waiting less time, it in effect advances the timing.
The dealer can't change the timing. They can "flash" the computer with updated software but anything that affects ignition timing for any given set of conditions would have been programmed in at Chrysler. They take into account performance, fuel mileage, spark knock, and most importantly, emissions when they write the software.
Turning the distributor only affects the camshaft position sensor which determines when an injector will fire. If you get that set wrong, it might fire while the intake valve is partially closed. The fuel will just sit there until the next time the valve opens but that can cause some of the fuel to condense on the cold back side of the valve. Liquid fuel doesn't burn or contribute power. What doesn't vaporize quickly just goes out the tail pipe, wasted.
Tuesday, July 26th, 2011 AT 2:26 AM