2000 Protege sometimes won't start

[Bobscar]

Our 2000 Protege starts normally except for about every 10th try it won't fire (starter turns engine okay). Since the "check engine" light is on, we took it to a shop to get the diagnostics read - the code said engine temperature sensor. After that was replace, no difference. Had the diagnostics read again and it said vacuum leak. I checked all the vacuum hoses and all looks fine. We are at a loss right now - any suggestions?

[rd_turbo]

Wasn't there an ignition coil recall? I remember my wife's car doing that (once or twice max) prior to the recall. The new part corrected the problem.