Originally Posted by xfree143
I'm running 40psi but it is randomly loosing pressure to 6lbs. I have to shut the car down then start it again and it's fine. It may go a day or two before it does it again. It's driving me nuts, I have changed the fuel filter and the fuel pressure sensor at the rail but it's still doing it.
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When it does that, leave the key on and test points with a voltmeter. Maybe even with the engine running. I would check before and after the relay and before and after the fuel pressure regulator. Also test right before the fuel pump. Maybe check the fuse in the box. Ive had light bulbs and fuses "go bad" but still sometimes work for no reason. That might tell you a lot. That's what I would do. Otherwise you can get your parts shotgun out and start replacing **** lol.