Known good install, will not start
Quote from bdhulderman on January 21, 2021, 6:53 amQuote from rockyroadster on January 21, 2021, 6:40 amQuote from bdhulderman on January 20, 2021, 1:58 pmI guess the first thing I would check is your voltage reading at the wire going to the fuel pump with switch on and while cranking. If with the switch in the on position, your fuel pump wire voltage drops way below 12 when your pressure is not reading near 60, there must a problem with fitech not reading fuel pressure correctly, because it's suppose to maintain pressure with the switch to on. If this is the case, I would connect the fuel pump directly to voltage with the key on and put in a external regulator. Could be your fitech internal regulator has failed.
So it works like a regular factory port injection, where turn the key, fuel pump turns on, gets pressure, pump turns off (not sure about that) but pressure holds? So the pressure regulator is saying, I have pressure, turn off? With a running engine, (hopefully I have one some day) does the fuel pump turn on and off or even some duty cycle to maintain pressure?
The other thing noticed is when the fuel pump is running, it is returning all of it back to the fuel tank at high pressure.
Thanks for your input!
Yes, turn key to on, pump runs until pressure is reached, pump turns off. If pressure starts to dip below target, pump starts up again to maintain pressure. Regulator just allows enough fuel to return to the tank to keep the fuel pressure from exceeding target pressure. It opens when the pressure exceeds target. I also put in a one way valve in the fuel line, so that when I turn the car off to go into a store or something and come back out, it will still read the target pressure and I can just immediately turn the key to crank.
How does it know if pressure dips below target? Is there a sensor, not the regulator right? Can you read pressure on the handheld and see what it is seeing?
Quote from robanzac on January 21, 2021, 2:39 pmIs the Pump pwm setting correct ?
main menu> pro tuning> initial setup > fuel pump control
It needs to be set at 75 with a normal efi fuel delivery set up i.e tank - high pressure pump - throttle body- return to tank
If you are using a Fitech fuel command center for fuel supply then it needs to be set at 40.
Operating pressure should be constant 58psi
Also - are you using the correct port for fuel return to tank ?
There is only one, the other three fuel ports are all inlets (you block off the two you don't use)
I'll look at that this weekend. Yes, my inlet and return are hooked up correctly. I'm using the inline fuel pump and return to the tank. Thanks
It doesn't really matter, I just explained how it's suppose to work, how it mechanically does it isn't really important. If it's not doing what I said, than there is something wrong. And no, you can't read pressure from the fitech, that's what your fuel pressure gauge is for.