115 and 90 bhp Engine Changes - NA (MKI)

Taken from the Mazda Workshop manual (12/94)


The purpose of the modification is to increase the low speed torque by changing the valve timing and compression ratio.The following parts have been modified The configuration of the camshafts have been modified:-

Valve timing

Intake Valve Opens 5* BTDC

Intake Valve Closes 40* ABDC

Exhaust Valve Opens 55* BBDC

Exhaust Valve Closes 5* ATDC

The configuration of the pistons have been modified

Compression Ratio - 9.0:1

Fuel & Emission Control System

According to the readoptaion of the B6 engine model, the following changes have been made.

  • Injection method has been changed from the two-group injection to the sequential injection.
  • IAC load correction has been added according to the addition of the rear window defroster signal input to the ECM.
  • IGF signal input to the ECM has been discontinued.
  • Signal names have been changed as follows. NE = SGT & G = SGC
  • Diagnostic trouble codes No. 01 have been discontinued.
  • Vehicle speed sensor input have been added.
  • In the exhaust system, the front pipe and the parts after it are the same as that of the BP engine model.
  • The heated oxygen sensor has been adopted and its instulation position has been changed.
  • The fuel tank capacity has been enlarged and the cruising range has been increased accordingly.
Features - Excellent drivability and improved engine performance due to Squential mulitport fuel injection