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fuel pump and o2

Posted: Fri Aug 15, 2008 8:15 am
by 195suz
In the mega manual they show the 12v for the o2 coming from the output wire of the fuel pump relay. Is this correct for use with a wiide band o2 sensor for the power to cycle on and off to it?

Re: fuel pump and o2

Posted: Fri Aug 15, 2008 9:10 am
by SQLGUY
Interesting question.

For my setup, although I'm using a narrow-band sensor, I installed a "main" relay to provide ignition-switched 12V to the injectors, HEGO, coils, and Microsquirt. The fuel pump relay only feeds the fuel pump. I did my setup this way to ensure that Microsquirt was getting an accurate reading of 12V feeding the injectors and coils.

On the other hand, you won't be going closed-loop until the engine is warm anyway, so having the WBO2 power up when the engine starts should be OK.