This is in continuation to my question Fast Idle and High Fuel Consumption. I just bought a Manual 97 Mazda Lantis 323 1.8L DOHC 16 Valve BP ( apparently called a Protege in the US ) which has a fast idle and is consuming lot's of fuel, giving black smoke out the back if you rev the engine.

The previous owner told me that he recently replaced the throttle body and attached TPS with a second hand one from the same model automatic version:

Throttle Body Front View

I want to know if this makes a difference - it seems to me from the answer to my previous question that the TPS on the automatic and the manual operate differently.

  • It's not that it *is a Protege here in the US, but that it has the same drive train. We had a 323 in the use which morphed into the Protege. I don't know why Mazda thought they needed to be all confused about such things, lol. Oct 10 '14 at 10:00

The vehicles engine map will be the differance. If you are using a throttle body spec for a differant set up then it is bound to be wrong. The TPS may also vary on model to model.

  • What is the vehicle engine map? So you are saying it would adversly affect the engines performance? Could you explain in more detail? Oct 11 '14 at 6:52
  • For a full and proper understanding of the subject I would recommend reading the American Legend-Jeff Hartmans book How to Tune and Modify Engine Management Systems. The basic idea is that every sensor on the engine management system produces a signal for every state of operation it at. The computation of all the signals together decide the engines operation. When the vehicle is produced it is with a set of sensors and equipment that are subject to this computation. This is known as the engine 'map'. Change anything on the engine then it puts the map out. Oct 11 '14 at 9:03
  • What if they put only the automatic throttle body but left the original sensor from the standard? The previous owner claims he drove it like that for six months with no problem. He's not sure if one or both were changed. Oct 14 '14 at 7:29

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