2000 chevy montecarlo 3.4L, Engine cranks but dont start.

IS THIS A RUBBER CAM BELT DRIVE, IF YES IT IS BAD
rs415 ,NO SWIFTS IN USA 2007
M15A 4-cyl 1.5 (BUT IS CHAIN CAM)
SO IF COMPRESSION AND SPARK ARE GOOD?

THEN WE DO TEST FUEL, CAN-0-SPRAY TEST FUEL
IT MUST START OR ENGINE HAS PROBLEMS
FUEL DRIBBLE TESTS ARE 99% USELESS IF NOT DRY.
ONLY FUEL PRESSURE MATTERS, FOR SURE CRANKING
ANY DEAD ENGINE, AT PSI SPEC. PRESSURE.
M15A HAS VVT, IF STUCK VVT,STUCK ADVANCED,
THIS TO CAN FAIL.
ALL SPARK GOOD X4 , SO TEST FUEL IS NEXT
SPRAY IT TO INTAKE MAIN PIPE, FOR 3 SECONDS
AND ENGINE RUNS FOR 3 SECONDS AND STOPS
REPEAT AND BE SURE ENGINE SOUNDS GOOD.
IF YES FUEL PRESSURE IS DEAD WRONG

You'll need to verify spark at the ignition coil secondary (coil wire that goes to the ditributor). If you dont have a spark tester, remove plug from cylinder 1, disconnect coil wire from distributor and connect to the plug you removed and ground plug to engine steel, have someone crank engine and observe spark.

Before you remove spark plug, crank engine for a few seconds, then promptly remove plug. If its wet with fuel then at least you know injectors are working. If dry, then likely injectors are not activated by ECM. Go ahead and confirm spark and then figure out why no fuel from injectors.

Make sure battery has a full charge. Engine cranking, if you have no spark at the plugs, no fuel injector pulse, and other than the initial prime, no fuel pressure, check for rpm signal, that comes from crank sensor. If no rpm signal, the vehicle won't start. W/o testing I can't be sure the problem is the crank sensor, there might be other issues? Just my opinion.

Engine sensors , mass air flow , coolant temp , also fuel pressure and flow . Suggest you have a qualified repair shop look at it with scan data .

056 Engine Hard to Start or No Start Misfire Scan Data
058 Engine Hard to Start or No Start Lean Fuel Condition
059 Engine Hard to Start or No Start Current Test for Fuel Pump

046 Engine Hard to Start or No Start Scan Data for No Start

Excessive cranking will put too much fuel into the engine. Have you tried holding the gas to floor and see if it starts. That will help clear out excess fuel from continued cranking.
Check for spark at a sparkplug wire. This will tell you if ignition system is working. You need to see a blue snapping spark to know ignition is good. If you are not sure how to check for spark, have someone help you. Easy to get a shock when checking for spark. You need the metal end of the plug wire just 1/8 inch to 1/4 inch away from a metal bracket or bolt on the engine. Hold it steady while someone cranks the engine over-watch for a strong blue spark to jump from metal end of wire to the engine. If no spark, your ignition system needs checked. If spark is good, have the fuel pressure checked-maybe it is getting too much gas.

listen for fuel pump when u turn key to on [not start] should hear a hum-check for pressure at fuel port -if pressure need to start checking sensors a bad crankcase position sensor--camshaft position sensor --bad egr valve--can shut down and not allow start those components sometimes dont throw a code

It has good spark then? Have you pulled a plug or two after prolonged cranking to see if plugs are wet with gas? You said pump was working, have you checked the fuel pressure? Nothing in your comment about the injectors-that's why I asked if plugs were wet.

Check the fuse for injectors, verify that power is available at all injectors with key in ON. You can check the injector circuit with a "noid light" available at any parts store-different sizes, so get the one that fits your injector connector. Just plug the light in and crank the engine over. If circuit is good, the light will blink. If it doesn't blink or if it lights up and stays lit-the circuit is not right.

All of this is to see if injectors are pulsing and spraying fuel. Do the same with spraying starting fluid into the air intake and cranking motor. If engine now runs for a few seconds, then you know it was a fueling problem.

If you are getting spark and the engine tries to run on starter fluid, then you have lost fuel. Check that you are getting injection pulses at the injectors and check the fuel pressure at the fuel rail at the injectors. Check for power to the fuel pump when the engine is cranking, If you get no power to the fuel pump when cranking the engine, check fuses and relays. If the pump is running but you have no fuel pressure, check the fuel filter and fuel pressure regulator and replace any that are faulty. If the injection pulses are missing, check the supply relay which supplies power to the injectors first ( the injectors are earthed by the ECU) Disconnect one of the injector plugs and using a test light (buy one from a auto parts store) clip the end to a good earth on the vehicle body, switch the ignition on but dont start the engine, then probe the two connections in the injector plug. One of these connections should be active all the time with the ignition switched on. If it is, you may have a sensor failure (crank sensor etc), if it is not, check fuses and supply relays. A word of warning, the wiring you are dealing with is connected directly to the engine control, if you make a mistake, you can cause irreparable damage so if you have any doubts, take the vehicle to a professional..

Have you checked the fuel pressure? Fuel pumps are a common failure item on those trucks. Pick up a cheap fuel pressure gauge and hook it up to the shrader valve on the fuel rail. With the ignition on and you should have 55-65psi. Even if it's a few psi below spec it could stop the engine from firing.Once you determine the fuel pressure isn't adequate make sure you have a good power and ground at the fuel pump. If that checks out, time for a new fuel pump module. I recommend only replacing it with an AC delco unit, I've heard bad stories about aftermarket replacements.
You could also spray some carb cleaner or starting fluid in the throttle body and crank the engine over. If it runs for a few seconds after spraying starting fluid in you know you have a fuel delivery problem.

Have you checked the fuel filter? Have you changed it EVER?