The inertia switch is located just to the left of the clutch pedal, and in that area for automatics as well. It's a little black box with a button on top. This switch allows power to the fuel pump (among other things), so if the connection is intermittent, the power to the pump will be also. The theory behind the switch is that power will be shut off to the pump in the event of a collision or roll-over to reduce chance for a fire. The switches are known to be a problem item. Putting good fuel in the car should not cause poor performance. This probably has nothing to do with your problem, but I had a "bucking" problem some time ago, and I traced it down to a spark plug wire coming loose at the distributor. All I had to do was "plug and play". Toby Peterson VIN 2248 Winged1 --- In dmcnews@xxxx, "Adam Price" <acprice1@xxxx> wrote: > My car also began bucking this morning for the first time. Fuel is > completely full and voltage levels normal. I put premium gas in it for the first time since I;ve owned it. I know these engines are rated for 91 octane, but premium is 92. Could this adversely affect the engine performance? > > Where is the inertia switch? > > Adam