Fuel pressure regulator help please!


New Member
Mar 10, 2020
I am in desperate need of help! I'm working on a 96 gt. I have installed an on3 turbo system. I'm running a MS3X for a computer. I am struggling with my fuel pressure. I have a kirbin regulator. So here is what is happening. As the car runs the fuel pressure progressively drops. I have it set that when i turn the fuel pump on its at 45psi with the engine off. I start the car and it maintains 45 psi for a few min with the vacuum line connected to the manifold. If i unplug the vacuum line and plug it it jumps up about 10psi. The car is making around -10psi of vacuum at idle so this makes sense to me. As i let the car sit and idle the pressure progressively drops. If i let it run long enough it drops to 22psi. I just installed a -6 feed and return with the appropriate fuel hat to try to solve this problem. I thought maybe i was boiling the fuel with the 340lph pump. Sadly the problem is not solved. To troubleshoot this problem i have tried running the fuel pump for 1 hour with the engine off. The pressure actually climbed about 2psi during this test. I also tried heating the fpr with a heat gun during this test thinking maybe it was getting hot under the hood and hanging up. No change in fuel pressure. I have verified this with both the fuel pressure gauge on the ms3x and a mechanical gauge hooked to the same source. What am i missing???
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Nov 21, 2020
There are other posts on this forum concerning fuel pressure issues. If you have not read them; it might help give you some ideas. Im not hip to fuel pressure diagnosis so I would not be of any additional help.