Originally Posted by
kls2020
I have just such a tool at home but used a Fluke pressure calibration set instead . Having the ability to increase air pressure in 0.1 pound increments I was able to verify the new regulator was cracking open at 134 PSI while the original regulator off the motor was opening at 133.8 PSI and both were very consistent . I figured gasoline being thicker that air would require a little more pressure to open the regulator valve .
I am suspecting the ECU fuel pump driver circuit now though I don't think I've ever read anything about a failed ECU making a pump have high pressure output . I am too tired to check it tonight but was wondering if the fuel pump driver uses PWM to control the pump voltage ?