1990 Chevy Lumina Fuel pressure test

Pressure is tested with key on engine off and should read 41-47 psi for 3.1 and 40-47 3.8 So replace the fuel pump and you are good to go. You can check the filter, but I haven't come across one that clogged and still run! Here it is from the book:
Fuel Pressure Check (PFI) 1. Relieve fuel pressure as previously described in FUEL PRESSURE RELIEF (PFI). Connect Fuel Pressure Gauge (J-34730-1) to fuel pressure fitting on fuel rail. 2. With gauge installed at fuel rail connector, turn ignition on. With ignition on and engine off, pressure should read within specification. See SPECIFICATIONS - 4-CYL article (for 4- cylinder models), See SPECIFICATIONS - V6 article (for V6 models), See SPECIFICATIONS - V8 article (for V8 models). Start engine. Pressure should drop 3-10 psi (.2-7 kg/cm 2 ). For more details on fuel system pressure testing, see SYSTEM/COMPONENT TESTS article.

No it's probably OK, this system is designed to bleed the pressure off quicker than most, as long as it's OK with key on engine off and drops 3-10 psi on start up, it's OK.

When it reads zero check for power at the pump, use a volt meter. The pump is designed to run only 2-3 seconds so hook up the meter and get a friend to turn the key on.

The pump is inside the gas tank, jack up and place on stands, then unplug the connector at the pump, test gray wire and ground, meaning black lead to ground red lead to gray wire, this gray wire comes from the pump relay. At least 10 volts minimum is what we want. And you should here the pump run for the 2-3 seconds.

- Check the following items. Ã Â Â Check fuel pump relay. To do this, connect test light between fuel pump test terminal (terminal "G" of ALDL on most vehicles) and ground. Turn ignition on. Light should illuminate for 2 seconds. If not, see FUEL PUMP RELAY in SYSTEM/COMPONENT TESTS article. For location of fuel pump test connector, see COMPONENT LOCATIONS in the article SYSTEM/COMPONENT TESTS in this section. Ã Â Â Check for poor quality or water contaminated fuel. Ã Â Â Check that TPS is not sticking or binding. Ã Â Â Check EGR operation. Ã Â Â Check for a leaking injector. To do this on TBI systems, disconnect injector electrical connector at injector. Crank engine and watch for fuel leakage. Ã Â Â Check that resistance of coolant sensor circuit or coolant sensor is not too high. See CODE 15 chart in appropriate TESTS W/CODES article in this section, or the SENSOR RANGE CHARTS article in this section. Ã Â Â Check ignition system for a worn distributor shaft, bare or shorted wires, incorrect pick-up coil resistance, loose ignition coil ground or moisture in distributor cap. Check for adequate spark using Spark Tester (ST-125). Ã Â Â Check for shorts by spraying plug wires with fine mist of water. Ã Â Â Remove spark plugs and check for wet plugs, cracks, improper gap, burned electrodes or heavy carbon deposits. Ã Â Â Check for correct fuel pressure in all speed ranges. Ã Â Â A faulty in-tank fuel pump check valve will allow fuel in lines to drain back to tank after engine is stopped. To check this condition, turn ignition off, disconnect fuel pressure line at fuel rail, remove filler cap, and connect a radiator test pump and apply 15 psi (1.0 kg/cm 2 ) pressure. If pressure will hold for 60 seconds, check valve is okay. Ã Â Â Check that PROM/MEM-CAL in vehicle is correct for that vehicle. Check with dealer for latest application information. Ã Â Â Check for restricted exhaust system.
See you in the am, early riser, so early to bed, 8:30 in my location 1 1/2 hour past bedtime!

Well look for any kinked or crushed pipes and rap on the converter and pipes, if the converter broke up inside and pieces got wedged in pipes of the muffler, it cause it. The other thing is, your fuel pump should slowly leak down from 42, it should not happen as fast as it seems to on yours, the pump could be jamming and un jamming. Test for exhaust blockage with a vacuum gauge, hook it up to manifold vacuum, raise idle to 2000 rpm, the gauge should hold steady over 15hg, if it falls, the exhaust is blocked. My money is on the fuel pump, but you never know!

All of the above! Check the injectors resistance they should be 12.0-12.4 ohms If one is bad it can wreak havoc in many problems, from stalling when hot to no starts. Fuel pressure regulator on PFI Port injected, (injector for each cylinder) has a vacuum operated regulator, if any gas is in the vacuum hose, replace it, if the fuel pressure should drop 4-7 psi with the vacuum hose attached to the regulator, than with it disconnected, also check for vacuum at the line. If you still loose pressure fast, replace the pump.

INJECTOR BALANCE TEST The injector balance test is used to pulse the injector for a precise amount of time, spraying a measured amount of fuel in the intake manifold. As each injector is pulsed, a drop in fuel rail pressure occurs. This pressure drop can be recorded and compared to other injectors. An injector with a pressure drop of 1.5 psi (.11 kg/cm 2 ) or more, greater than or less than other injectors, should be considered faulty. 1. With ignition off, connect Fuel Pressure Gauge (J-34730-1) to pressure tap. Unplug harness connector at all injectors. Connect Injector Tester (J-34730-3) to one of the injectors. 2. Follow manufacturer's instructions when installing adapter harness. Ignition should be turned off at least 10 seconds to complete ECM shutdown cycle. 3. Turn ignition on. Fuel pump should run at least 2 seconds after ignition is turned on. Bleed air from gauge and hose to ensure accurate gauge reading. Repeat this procedure until all air is bled from system. Turn ignition off for at least 10 seconds. 4. Turn ignition on again to bring fuel pressure to maximum. Record initial pressure reading. Energize tester one time and note pressure drop at lowest point. 5. Disregard any slight pressure drop after low point is reached. Subtracting second pressure reading from initial reading indicates amount of injector pressure drop. 6. Repeat step 4) on each injector and compare pressure drop. Recheck injectors not within pressure drop range. Replace injector(s) failing second check. 7. If injectors are all okay, plug in harness connectors and review SYMPTOMS in H - TESTING W/O CODES article. NOTE: Allow engine to cool down to avoid irregular readings due to "Hot Soak" fuel boiling. To prevent flooding, the INJECTOR BALANCE TEST should not be repeated more than once without starting and running engine. CAUTION: To avoid possible vehicle fire, wrap a shop towel around fitting to avoid fuel spillage.