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low fuel pressure , random misfires, hard starting
it has to be extreme for a filter to be blocked
the same indications for a blocked filter or problem pump can be from a faulty EVAP system or EVAP purge valve not venting and the tank is in a vacuum condition
read the fault codes first
Check the fuel filter and fuel pressure regulator. They are part of the same assembly and are located on top of the fuel pump. To replace the regulator # Disconnect fuel supply line at the Filter/Regulator nipple and releas locking spring tab (2 in diag.) on the regulator, then turn counterclockwise and pull out. To test regulator use a gauge like this in fuel lines:Pump Pressure Tester. Pressure in 2003 should be 58psi (48 in 2001 engines). Pressure will drop of about ten psi when you start engine.
There is also an automatic shut down relay ASR. If problem is the ASR the
pressure will go down when the relay cuts off power to pump. Read
voltages and see if the problem is electrical first before going for the regulator.
if your oil pressure gauge is reading low, the sensor, instrument cluster gauge or the pump is bad. remove sensor and use an oil pressure test gauge. reading should be measured and verified against manufactures specs. if the pump is bad, damage to the engine will result.
Check for correct fuel pressure. Connect pressure guage to schrader valve on fuel rail. Turn key to ON position without starting engine. Fuel pressure should be between 55 and 61 PSI. If it is too low, replace fuel pump in tank and fuel filter.
does it get spark? you can purchase a fuel pressure gage and check the pressure yourself. Also turn on the ignition and then get back by the fuel pump and listen for it. if you can't hear it run then it needs to be replace.
SOUND LIKE THE ELECTRIC LOW PRESSURE FUEL PUMP CHECK FUSE TO SEE IF PUMP GETTING POWER. IF NOT REPLACE FUSE AND CHECK THE WIRE TO PUMP.IF PUMP IS GETTING POWER..REPLACE FUEL FILTER FIRST.IF IT DONT HELP.COULD BE THE ELECTRIC LOW PRESSURE PUMP. FAULTY. IT PUMPS DIESEL FUEL IT INTO INJECTION PUMP TO BE PRESSURIZED TIMED AND INJECT.SEE IF LOW PRESSURE PUMP DONT WORK THE WHOLE ENGINE WONT RUN.THE INJECTION PUMP NEED FUEL FROM LOW PRESSURE ELECTRIC PUMP TO RUN ENGINE.
Check your fuel pressure at the Shredder valve, you should have 60PSI to 65PSI. If you have less then that or more then that your going to have problems with your fuel injection system. The other thing to is to check your fuel pressure regulator. Hook up the fuel pressure gauge and turn the ignition switch to the run position to activate the fuel pump. Once the pump stops pressurizing the fuel line wait and see if your losing the fuel pressure excessively. If you are then your may have a bad regulator and it's leaking internally. The other thing to is may be a bad fuel pump, The good news is the fuel pump in the sending unit in your bravada can be replaced rather then the whole unit. If it is the fuel pump, Buy a heavy duty pump to install to your sending unit. Don't have them sell you the whole unit, pump alone is around average $60.00 other then the whole unit for $230.00.
Good luck and keep me posted, be glad to help