supraturbo1987

iTrader: (4)

I connected my fuel pump to my voltmeter and ran it into the car to see what the voltage is going to it under load. at Idle it was about 9.4v. Now, if I put any load on the car with driving (accelrating briskly to 3 or 4k without boosting) the voltage would drop to the upper 8's and that is where I feel the "limp mode" feeling I have been getting. I am getting smoke too...pretty bad on a hot startup, or say if I am driving for a 1/8 mile or less in 2nd gear, as soon as I come to a stop, smoke. Almost a bluish white. My temps are good and vac is between 15 and 18....

According to Dale Clark's write up:

http://www.clubrx.org/default.asp?AC...=71&id=5&mnu=5

he wasn't happy with 11.5 at WOT...I am a little worried for what mine would be..

Trev

supraturbo1987

iTrader: (4)

Okay, I ran a hardwire to the Fuel pump and my voltage at idle and under brisk acceleration was about 10.75. Still have smoke on a hot start up, and after I let off the throttle following a 1st or 2nd gear constant drive...in fact, it smells like burning rubber or something. the car was still doggy and hesitant despite the more voltage. I am really getting discouraged. Not sure what I should do

cewrx7r1

iTrader: (2)

First: the pump runs of two circuits.
Idle/low load where the voltage is reduced by the speed control relay and resistor.
High load where the speed control relay bypasses the speed control resistor and supplies full voltage to the pump.

Second: Mazdas poor wiring only allows about 11.8 volts max to the fuel pump even with the resistor bypassed.

Third, I was the first to tell how to rewire the stock fuel system to still work as Mazda designed it but give about 2 more volts to the pump.

Others have rewired for more voltage but bypass/disabled the speed control. This causes higher idle fuel pressure and will wear out the pump faster for a street car.