Fuel pressure regulator bad on brand new out of box unit
So I purchased a new go EFI 600, installed on my BBC, and have had nothing but problems that I believe I have now tracked down to a bad fuel pressure regulator.
Brand new tank, new 255 lph pump, all new lines, into a brand new 30 micron filter, then straight to the fitech fuel inlet. I was using the internal FPR on the unit and have never seen more the 55 psi on my gauge. When you Rev it drops, I have seen it go as low as 40psi under a hard blip of the throttle.
I ran my pump direct to the battery to be sure it wasn't a power problem, no change. I changed my fuel line from 1/2 to 3/8, no change. I then dead headed the return line and my pressure pegged the gauge out at over 100 psi. After more searching the forms I have seen posts with similar problems but never any posts saying they were solved. I believe that straight out of the box either my FPR is either bad or the incorrect psi rating. It is supposed to be at least 58 psi. I searched my area to find a replacement FPR but wasn't able to confirm what regulator they used for the unit. Since the regulators I found at the parts stores were all over $100, I've chosen to go with an external adjustable FPR for not much more money, as that's what I've seen come across the posts here. I will report back my findings when the regulator shows up and I have it installed.
Anyone else run into this, and have a definite answer if the internal FPR was their problem.
Quick update, I received a message from the fitech technical support with some conflicting information about the fuel pressure needed. I'll post the message below. I've already confirmed that voltage is not an issue or any other issues they brought up about tank venting and filter issues.
Fitech rep:
The pressure does not have to be 58 but we do not want to see big fluctuations in the system. There is a PWM feature in the unit under initial set up and then engine set up. Default number is 74.9 so the pressure will move a since we are dropping voltage down some. Depending on the fuel pump you are using some pumps like the Walbro pumps do not like any voltage drop so I would turn this to 100 just to be sure and watch pressure again. We are not over driving the pump doing this but just running full voltage to it. The 255 you have should be good to 600 hp and generally under low load you will not see an issue even if the pump is small you would see a lean condition under heavy load when the pump can not keep up with demand.