My Mazda 626 is a 2001 LX 4cyl my problem is that the engine turns but won't start it sounds like it wants to start at times but doesent,I've already chekd for spark has good spark I've checks gas and gas pressure also changed gas filter I've changed the coil box for spark plug cable I just can't find the problem I had a mechanin come look at it he said it was the timing belt I opens the engine and lookd for nicks or slipd teeth on the belt but found nothing belt looks to b in great condition I think mechanic is tryng to screww me over please help I would really apriciate it thanks

And engine needs fuel, spark and air to run. If you are sure you have fuel and spark, the timing is the last thing to check. Your engine is provided with external alignment marks. take out all of your plugs, and by hand, turn your engine over until you see your harmonic balancer (pulley your belt is on at the bottom of the engine/crank) alignment marks meet with the marks on the engine block. Next you need to look at your cam gears. You might have to pull a plastic cover, or the valve cover off to see the cam gears. The cam gears have alignment marks as well. If all marks line up together at the same time, timing is not the issue. the timing belt is an iffy design. The timing belt tensioner could be warn out and only show signs or being warn out every now and then. your tensioner could have loosened up, caused your belt to jump, and clamp back again.