Some Mazda engines have a solenoid valve on the vacuum line that goes to the fuel rail. This is used to raise the fuel pressure on a hot restart and avoid fuel vapor in the fuel rail.

This valve is not really needed with rusEFI and can be removed, in it's place a longer than normal "prime duration" should be set in the "fuel pump" dialogue. (suggest 4-6 seconds).

Engines known to have this valve:

• MX5, 323 and protege B series