I've got a 2000 Dodge Durango with a 5.9 literally in it. Been dealing with a fuel pressure issue. Fuel pressure from the injection rail is maintaining at 80psi (should be around 45-55psi). Before I swapped out the pressure regulator it was maintaining around 72psi. I've tested injectors, tps, Mas, checked for crushed lines, rear vents off the tank are clear. Can't get it to throw a code either. The pressure is maintaining so high that it's continually flooding the oil reserve with fuel. Looking for some ideas as to what's going on here. Any help is greatly appreciated.

ECU, pressure regulator, o2 sensors?

The internet isn’t really a solid place to diagnose an issue like this, I’d bring it into a shop if it’s worth it to you.

E: does it idle rough?

This post was edited by ozzyarmy3 on Aug 29 2022 06:09pm

The ECU seemed fine, a buddy of mine brought home his dealership computer and ran test on everything he could. The pressure regulator on these is also the fuel filter. I swapped it out with a brand new high end regulator. It was maintaining 72psi with the old one, and 80psi with the brand new one. Possible faulty new part? It does show a fault at the O2s, they are being delivered as we speak. Although I've been told by quite a few mechanics that an O2 sensor failure shouldn't cause such a spike in psi. Figured worth replacing anyways.

I know the web isn't the best place, but it's still another source of information. I've had multiple shop mechanics at our garage to help diagnose it. When we first start going through and testing things, we were able to start the vehicle with all of the plug wires disconnected, coil disconnected from power in and power out. It ran like absolute dog shit. But it somehow managed to fire under the sheer compression. This one's been work lol

prolly just ls swap it

I would check to see how much amperage and voltage (could be a short to voltage) is going to the fuel pump. id also make sure the correct fuel pump is in the vehicle. id also double check fuel pump gauge. the gauge could be bad and reading incorrectly.

typically, if a pump is pushing out more than it has had some kind of aftermarket system. when i was boosting the FIL truck, we put a controller in for the fuel pump that boosted the voltage up to increase what the pump motor puts out while under boost.