Fuel Pump Relay Question
 

Another question regarding how my Microtech ECU has been wired...

I have attached a picture of the fuel pump relay which was installed at the time, I presume, that the LT10s was installed. It looks like it follows the Microtech wiring diagrams. I am in the process of pulling the motor and haven't traced all of the wires yet but it looks like at least the correct colors are going to/from the relay.

So here's my question - does the addition of this relay mean that the stock system of lowering the voltage, and hence the output, of the fuel pump during lower rpms is not being done? Looks to me like the fuel pump is always on. Does this affect the life of the pump? Wasn't that why Mazda used the resistor setup?

Thanks again for any help you can give me on this.

Jeff

If it was done correctly, the entire stock system is bypassed and the pump is running full out anytime the engine is running.

Is that a good thing from a reliability standpoint? Car will be only street driven - no racing. Didn't Mazda use their fuel relay/resistor system to ensure longer life on the pump? Am I to expect early pump failure this way?

I realize that the trade may be a pump versus an engine if the fuel pressure isn't adequate but I would sure like some of your opinions on this.

Jeff

Extend pump life?

Ill wait for someone to prove that before making that statement.

Running flat out all the time is the better way. More consistent. No variations in fuel pressure.
You are not to expect a pump failure etc.

I don't think it has any bearing on pump life. Most vehicles run the pump wide open all the time anyway. I think Mazda did it for better fuel control down low with big injectors.

I am not an engineer or a scientist so dont flame me for guessing a little here, but i would have though running the pump with more fuel pressure would give the bigger injectors a better spray pattern, hence better tune at the end of the day.

and 550cc injectors are really not that big.

Compared to piston cars they are.