Could I have a bad fuel pressure regulator?
It took some time but I got my Go EFI-4 600HP dialed in it has been running great. For the last week it was getting harder to start. Yesterday I was going off road camping and it would not start, just cranks. Fuel pump cranking out pressure to the fitech. When I pour some gas down the throttle body it will run momentarily. I removed the return line from the unit while pump is on and gas was flowing through it. Pulling back on the accelerator pump and looking down the throttle body I see no gas coming out. I put the carb back on went camping. I need your thoughts please.
a. There is no accelerator pump. When you turn the key on there is a prime function, adjustable through the handheld, usually 4 or 5 seconds, you should hear the pump run and see fuel coming out of the injector rings in the throttle body.
b. A pressure gauge in your supply line is a must, saves a lot of heartbreak if you have a problem [like now]. I put mine just before the throttle body fitting, I have seen pictures where people have fitted them to the alternate supply port on the throttle body.
c. I replaced my pressure regulator because it had a faulty 'o' ring that was not a common size, instead of tracking one down.
d. Some owners disconnect factory regulator and fit an adjustable external unit, BUT fit a pressure gauge first, to confirm if it is the problem before you start throwing dollars and time around.
If you are getting the correct amount of fuel pressure with the gauge, then it could be what was happening to my wife's 600. She wasn't getting enough voltage while cranking. Unlike a carb, EFI requires at least 11 volts at the fitech power wire while cranking the engine over, or it will have trouble starting. One way to test this, is to put a battery jumper on the car battery while cranking to see if it helps. I bought a small battery jumper IM29 by Imazing and connected that up to battery and it fired right up. I've since put in 800 CCA battery and that worked great as long as you drive it regularly to keep the battery charged. Even if that gets a little low, it will have trouble starting, even though the engine rotates over well. The ultimate solution was what I did then.
Thanks, I am getting pressure to the fuel gauge right before the throttle body. Voltage is great. Pump runs like it should but no fuel coming out to the injector rings in the throttle body. Like I said it will fire and run momentarily by putting gas in it.
Couple of screws gets the regulator off, I had an 'o' ring that must have been damaged during assembly [needs a bit of lube] that was partially blocking the flow, also the regulator can block up from any crud that may had inadvertently been in the supply line, hit the key with the regulator off to check flow, even put a dummy plate over the mount hole to see if you get flow out of the injectors, check vacuum hose while unit is off. I don't know if all the injectors can fail to allow fuel through, that is beyond my knowledge.
Quote from LAZYMON on September 5, 2020, 12:29 amThanks, I am getting pressure to the fuel gauge right before the throttle body. Voltage is great. Pump runs like it should but no fuel coming out to the injector rings in the throttle body. Like I said it will fire and run momentarily by putting gas in it.
If you fuel pressure is good, and you have full voltage, then if there is nothing wrong with your ECU, then it may be plugged. What are the fuel filters you are using, how many microns?
I had previously removed the regulator to have a look inside and all looked well, I will think about the plate idea or just buy another regulator. If it runs I know I found the problem and if not I have a spare regulator. I hate to just throw money at a problem though. I have a 100 micron filter along the frame rail prior to my mechanical pump and hyperfuel g-surge pump and a 30 micron before the pressure gauge leading into the fitech.
I have seen some posts saying that you can put a gauge in line with the pressure regulator but don't see how that is possible. It would have been a nice built in feature to see this at the handheld.
I need to pull the carb again and put this thing back on and troubleshoot some more. But I really needed to go offroad camping. This is on a 73 Blazer and I was really liking it more than the carb.
I'm having the exact same issue with my Fitech unit. I sent it back to Fitech a week in a half ago to be tested. They said my regulator was regulating too high (80psi). They replaced the regulator and flashed the ecu and sent it back. It worked great for two days and then the issue came back again this weekend.
I'm trying to figure out if a bad regulator can cause this issue or do I have a problem with my unit. Can a bad regulator keep the injectors from firing?
Did replacing your regulator fix your issue? If not, what did you do to resolve your problem? Thanks bro.
Well winter is over and I am getting the truck ready again. I did replace the regulator on Monday and it will not start. Seems like the injectors are not firing.
Have someone turn the key while you check if you are getting a prime shot from the injectors.