I have a 1992 Park Avenue with the 3.8L engine. If you''re starting from a dead stop and depress the accelerator pedal there is significant hesitation almost to the point of stalling before the vehicle will begin to accelerate. Likewise if going, say, 50MPH and attempt to accelerate the engine will usually begin to stall for a split moment, backfire, and then respond.

I''ve noticed that the mileage has fallen through the floor, dropping from a consistent 23MPG to about 17MPG.

The vehicle has 145K miles, and the plugs were replaced about 10K miles ago.

Any thoughts as to what is happening here?

Thanks,

Steve