Quick background..
One of my older mopars, swapped it to port Efi back in 2008. Megasquirt handles the fueling and timing.
I replaced the sock filter in the tank,/ sending unit/ pickup . Replaced the high pressure fuel filter and external fuel pump as well.
I started to have some odd lean / surging issues when the car got warmed up and driven for a few miles.
I have an older bosch adjustable FPR and it's been on there since 2008.
Everything else on the fuel system except has been replaced within the last 2 weeks. Surging / lean issue still exists and now I am now suspecting the regulator. With little load on the engine revving in park, the pressure remains near 40 psi and does not falter much. My pressure gauge is on the fuel rail so I cannot see Fuel pressure while driving.
Any thoughts / ideas appericated.
I've seen a lot of ways they can fail. Sometimes the most obvious sign is that they'll hold pressure ok at idle but it drops like a rock when you turn the key off... Or turn up the injector duty. I've also seen ones leak fuel into their vacuum line. You could use an electric sending unit and data log pressure with the MS, although that's easier on MS3 and tough on MS2. Or clip a temporary pressure gauge under the windshield wiper.
yes it feels fuel starved when I turn up the injector duty.. with my foot... so I have been in "limp mode" lugging it back home with low rpm and low load.
This could be a regulator or a dying fuel pump. If the system holds pressure with the key off, suspect the pump.
The pump is brand new but it's a chinese MSD unit. It could be faulty.
I have a regulator on order and I will change it this week.
I guess onto the 3rd fuel pump is a possibility too.
