My 99 monte carlo runs great but every once in a while it wont start it cranks over but the fuel pump never turns on if i let it sit for a few days it will start i always know when its going to start because at that time i can hear the fuel pump turn on do you think its the fuel pump or the relay or could this be something else this has happen a few times dont really take it anyplace now scared of getting stranded

I would start by checking the fuel pump...sitting for that long will rust the fuel pump

Sounds like a problem with the key switch, probably the security system. You may only have power to the fuel pump when the engine is cranking.
Is the security light on or flashing ?

I had a 2001 Impala that would crank and run for about 3 seconds and go dead it was the passlock system had to put the key in on position and let it sit for about 30 min and do a relearn it sounds funny but it worked on mine. Good luck

Check your fuel pressure. And your fuel pressure regulator.

Squirt some starting fluid in the intake if it starts and then dies yes its a fuel delivery problem. If it doesnt start at all check for spark at the plug wires then at the coil. If you have spark and fuel then it could be a number of things could be timing or crank sensor tps to name a few hope this will get you started at least.

check fuel pump quick check spray starter fluid if starts no fuel reaching throttle body if no start or gas is present at throttle body check for spark from distributor to coil pack

check the fuel pump and see is working properly, if the pump is good than the problems will be the crank sensor is faulty. what crank sensor does it sense the turning of the flywheel and it send a single to ecu, and ecu send a flow of power to turn on the fuel pump as long it sense the flywheel turning.

WELL, THEIRS A COUPLE OF THINGS THAT COULD BE WRONG, FIRST YOU DIDN'T SAY IF IT IS CRANKING OVER AND JUST NOT FIRING OR DEAD COMPLETELY, SO IF ITS CRANKING SIT IN THE CAR WITH RADIO OFF WINDOWS UP AND LISTEN CLOSELY TURN KEY ON TO THE RUN POS. LISTEN YOU SHOULD HEAR THE FUEL PUMP TURN ON FOR APPROX. 3 SECONDS IT WILL MAKE A BUZZING SOUND THIS IS NORMAL IF YOU DON'T HEAR THAT YOU MAY HAVE A BAD FUEL PUMP IF YOU STILL ARE UN-SURE REMOVE AIR CLEANER DUCT TO WERE IT CLAMPS ON TO ENGINE AT THROTTLE BODY YOU HAVE TO HAVE ANOTHER PERSON TO DO THIS HAVE FRIEND SIT IN CAR BEFORE THEY CRANK ENGINE HAVE PERSON HOLD GAS PEDAL DOWN THE PLATE IN THE THROTTLE BODY WILL BE VISIABLE WERE YOU REMOVED AIR CLEANER HOSE SPRAY A SMALL BURST OF STARTING FLUID INTO THEIR AND RELEASE FOOT FROM PEDAL NOW TELL ASST. TO CRANK OVER IF IT STARTS THEN QUICKLY DIES YOU HAVE A BAD FUEL PUMP.. HOPE THIS HELPS...

Sounds like the fuel is draining back towards the fuel tank, which is the reason for extended cranking till fuel reaches injectors. My guess would be the fuel pump in the fuel tank. It contains a REVERSE FLOW VALVE, which SHOULD prevent this. A visible way to check would to place a manual fuel pressure gauge on the fuel rail valve. After shutting the engine off note the degree of pressure drop, if any. Hope this helps

My car was doing the same thing. It would stall out while idling or even turning a corner. I ended up replacing a few sensors but the problem was the fuel injector pressure regulator. The check engine light never came on. It was leaking fuel through the vacuum side of the diaphragm. Disconnect the vacuum hose from the pressure regulator and if there are any traces of gasoline it needs to be replaced.