It just wont hold pressure at 58. Worked fine for a few months then started losing pressure. Fluctuates between 50 and 58. I replaced fuel filter, didnt help. I put in brand new racetronix pump with wiring harness. Held solid at 60 for about 10 minutes. Stopped for gas then right back to 56. Im not sure what else to do. Car only makes just shy of 700rwhp and I cant even keep steady fuel pressure. Im about to give up on this. Any last things to try before I lose my *** on this car?

Thats what I have. Im not super mechanical and didnt build the car myself used a shop so this isnt easy to figure out.

Thats a 1:1 boost reference regulator. Why arent you using the reference port to maintain full use of it?

Im not sure about the boost referenced deal. Thats what I thought it was. I thought it activates the secondary pump at a few psi. I have a gauge in the car thats what Ive been looking at. I can confirm its not the gauge because I burned the #8 spark plug. Also the pressure issue Im referring to is during normal driving and idle. It wont even maintain 58psi like it used to. Something happened at some point to cause a pressure drop.

Its a 2001 Z06 Im not sure what that means.

if your UPP pump is turning on, connect a line from the intake manifold to that barb fitting on side of the regulators red ha. This is your pressure connection. So for every 1# of boost you will gain 1psi of fuel pressure. Any questions just call CK.

The confusing part is this worked fine all winter. And the low pressure is during cruise and idle so boost reference shouldnt effect that correct?

You can disassemble and clean the fpr fairly easily and inspect for worn or damage pieces. If the pump, filter and wiring are new that is where I’d look.

Yeah I dont know what else it could be. The regulator in the engine bay from UPP regulates pressure during idle and cruise?

At all times

NO!

This is incorrect.

NO, do not connect a vacuum line to the regulator.

If you're not setup to be a full return system with eliminating the factory reg you CANNOT run boost refference.

If you're expierencing issues at idle/cruise it has nothing to do with the UPP fuel system. When not in boost the system is not only dormant, it is seperated by a check valve. Meaning the car runs 100% as if it weren't there at all.

Problems like that which are present durring idle crûise suggest something with your factory setup. Predominatly the factory reg. Over pressure on our system can kill the factory reg. Hence why you need to properly set fuel pressure, and NOT run 1:1 boost ref.

CK