Running rich and only on any 3 cylinders but dies when 4 injector connector re-connected. Fuel pressure 33 psi rising to 39 with vacuum line removed. Pin tested all power supplies, grounds inputs all good. Disconnect alternator and it runs great for only a few minutes on all 4 and then dies. Fuel pressure had risen to 100 psi. Open manifold valve on fuel pressure gauge to drop pressure manually but still running rough and improves when one injector disconnected. After shutting down and bleeding fuel pressure, starts and runs great but after a few minutes, repeats above scenario. ????? Tomorrow I will remove fuel rail to see what's going on in there and go from there. Any thoughts???

Mark Schlangen
Owner/Technician
Mark's Car Shop
Cedar, Minnesota, USA