Unfortunately that system doesn't have a test port so you have to tap into the fuel line at the fuel filter in order to install a fuel pressure gauge. It will require adapters, hoses and the fuel pressure gauge. Once you have a gauge installed, with engine off, you cycle the ignition key on and off several times until the pressure has peaked, it should read between 41 to 47 psi.
Where is the fuel pump fuse and relay on 1994 BMW 525i and how can I test to see why my fuel pump won't work
Have a fuel pressure test done. A 4.3L should have 60 to 66 psi, a 2.2L should have 41 to 47 psi.
Fuel pressure test. First thing to do is replace the fuel filter. If that does not help, then test the fuel pump with a fuel pressure tester. If you can't hear it run for a few seconds when the key is turned on, either the pump is bad, or the fuse is blown, or the fuel pump relay is defective. Even if you hear it running, it may be so weak as not to work properly.
Test volts to the pump. Shake wires and test again.Maybe a bad connection.
Check your fuel pump and fuel injectors. Have a fuel pressure and flow test done.
Fuel pump pressure test.
start the car, rev to 5500, if it sputters going up, not enough fuel pressure
I would suspect fuel delivery problems. Start with replacing the fuel filter. If it still has trouble have a fuel pressure test done to test the fuel pump and fuel pressure regulator.
You can backyard mechanic test it by removing the fuel line from the carb and crank it over, if fuel pumps out the line,the pump would seem ok. The manner in which the fuel pumps is critical, it must pump with some pressure not just ooz out.Be careful where the fuel spills also to keep safe.
Fuel pressure test at the fuel rail.
Fuel Pump Pressure Test Look at the Related links below for help.
A fuel pump pressure test could determine the condition of the fuel pump and fuel system.