Driving across to Narrogin (country WA) a couple of days ago, I encountered a strange one: Whilst cruising at 110kmhr, the tone of the engine changed very slightly, and I felt (I think) a bit of a twitch through the accelerator pedal. Noticing this, I tapped the accel pedal which would normally see the car jump from, say, 110 to 120 quite quickly, but instead the response was dismal. A very slow increase in speed, and the car seemed to labour to it. I pulled over, swtiched off, checked fluid etc, no overheating... nothing. Started up again, and the problem was gone. Hooray! A few hours later, same thing happened again - lost accel power. I came to the crest of a hill, put the car in neutral and coasted down. At the bottom, back into gear to accel out, and everything was fine again. Addt: I also checked the air filter So, any ideas? BTW, I was privy to a few laps around the speedway there and hit 160 at the top of forth (was a slight decline tho).