Mazda Miller Cycle engine

About 1-2 hrs after driving the TCS Off light comes on and then the TCS trouble light comes on and the car will not shift properly. Mechanic says goes into “Fail Safe MOde”. Going on 6 months now . The best mechanic in town and now the Mazda dealer have been unable to fix. If you shut car off and restart problem goes away for another few hrs, then comes back. Mechanics say no vacuum leaks and solinoid valves OK. Driving me crazy. Any help or ideas ??

did you ever get to the bottom of this? mine is doing it also. only in the mornings when it is coming up to temperature. once I stop and restart, it is good to go till the next morning when it is cold again. mine is a '98 millie S

I did not know Mazda had the Miller Cycle engine, can you tell me, in simple terms, how it is different?

The Miller Cycle engine has a camshaft that makes use of a supercharger by keeping the intake valves open well beyond bottom dead center of the intake stroke, into the compression stroke. Doing so actually increases the ultimate compression of the engine.

Not quite. The Miller cycle engine has a compression ratio of around 14:1. You are right about the camshaft profile, but it reduces the effective compression, not increases it. In the end, it acts like a smaller displacement engine on the intake stroke, but with a power stroke of a larger displacement engine.

You might double check that compression ratio keith. I seem to recall that the Miller engine was about 10 to 1.

The figure I got was from an article about Miller cycle engines in general from one of those Popular something magazines. It was one of those “look into the future” type articles and it was before the Mazda Millenia it the market. It was a long time ago but the 14:1 kinda stuck in my mind since most engines at that time were about 8:1.

It seems like the guy who designed it made his first engine out of a Chevy small block. Its really all about the cam profile.