Mazda 121 Engine Problems

IT SOUNDS as if the engine is running too rich, which could be caused by a faulty oxygen sensor in the exhaust. It's there to monitor the air-fuel mixture and send signals back to the engine-management computer. If it's faulty it could be sending the wrong message.

The first thing to do is drive the car yourself and see if there’s a pattern to what’s happening. Until then, you have even less idea of what’s going on and a diagnosis is all but impossible at that point. You might find that the car is cutting out after a period of driving (maybe caused by a dirty fuel filter) or when the engine reaches a certain temperature (possibly a sick crank angle sensor).

I’d also recommend an electronic scan to see if any fault codes show up. These codes can be very specific and will often lead you straight to the root of the problem.

IT'S at the high end of what I would expect, but it's hard to provide a reason without knowing if you live in a hilly area, if you keep tyre pressures up to the correct level, if the wheel alignment is within spec, and if the engine is in good condition.

Any time a fuel-injected car can’t get fuel from the tank to the engine, the number one suspect is the electric fuel pump. These are often located inside the fuel tank and have a finite lifespan. And when they stop, they just stop. That’s it; no warning and only a new pump will get you going again.

However, it’s also worth checking that you don’t have a blocked fuel filter or a kinked fuel line or something equally random that is stopping the fuel getting to the engine. Nine times out of ten, however, the fuel pump will be the culprit.