need some help here .please....have a 2000 Malibu ls 3.1 motor..followed a conversation a while back but can't find it... I have no fuel pressure....but in following previous thread new fuel pump didn't fix it ... they then talked about the switch not supplying the 12 volts..only 6 at the engine fuse block ....how can I determine if the swtich or pump is the problem ? thanks..ready to start working on it again....

 

I hope you got it solved by this time. If you fixed it, what was the cause? First check all fuses.
The oil pressure switch sometimes has a connection with the fuel pump. If it does, the oil pressure sensor cuts off the power to the fuel pump if it senses no or low oil pressure.
I was wondering if you had any trouble codes come up. Did the check engine light come on?
Did you have a code reader read the codes?
It's possible that a crankshaft or camshaft position sensor is giving a code to the computer and shutting down the power to the fuel pump.

 

if your theft light is blinking it's the passlock sys. to overide turn key to on, wait-- it takes aprox 10 minutes and the theft light will stop blinking and stay on, then turn ignition off then normally start the car…