I have a mazda 626 that is being used as a teenager runabout with lots of dents and lots of miles. Car is otherwise in excellent condition mechanically and has been taken care of before we bought it from a friend with 225,000 miles. The vehicle has started to simply stall out on an irregular basis when being driven. In trying to diagnose this I noticed that when left to sit and idle at 750 RPM after a minute or two it will simply drop rpms down towards 250 and then regain rpms up to the 750 to 1000 level. However, if accelerator is applied when the idle drops to 250 rpms it stalls. I'm thinking maybe fuel filter problems. Any ideas?

Thanks,

G.Norris

 

Check any vaccum lines.

 

My 2002 Millenia was doing the same thing. Dealership has had it for about a week. They finally called today and said it was the "throttle positioning sensor switch".