How the boost gauge on cluster works on Turbo II
 

HI I have a 1990 Mazda Rx7 GTU and make it Turbo II complete. I put a Turbo cluster and the boost gauge don't works. Any can help me to work with the problem?
Thanks Jose.

Jose,
Did you also install the boost pressure sensor that installs in the engine bay? This would be needed to make the gauge work since your car is non turbo and did not have that pressure sensor. Also, I don't know for sure but you may need to also wire up the sensor to the dash. I am not sure if they ran the boost sensor harness on the n/a engine harness. Look up the Factory Service Manual ( fsm) and study the wiring diagrams for additional info.
But my opinion is the factory sensor and gauge are trash.... I would light it up but not have it be functional. Insted get a quality, accurate aftermarket boast gauge and mount it elsewhere.

Pin 2H of the ECU is the Boost Sensor signal and this wire is part of the emission harness. The wire is found in connector FEM-02 located near the ECU. This wire runs to the Boost Gauge in the cluster on a turbo car. You probably do not have this wire properly connected to it. You have not stated what harness you are using. If the front harness is NA then there would be no reason for this harness to have a wire in FEM-02 running to a Boost Gauge in an NA since there isn't a Boost Gauge for a non turbo car so you have to make sure that the wire from pin 2H does in fact reach the gauge. There is also a wire in FEM-02 that is a ground wire which also runs to the Boost Gauge.


Look at post #2 in the link supplied and specifically the right diagram. At the right of the actual diagram shows the Boost Sensor wires and how they run to the gauge.

https://www.rx7club.com/2nd-generati...lowing-750202/