Chevrolet Repair: 2000 chevy tahoe 5.7, engine cranks, checy tahoe

Question
I have a 2000 checy tahoe with 225K on it. A few weeks ago the engine began acting very sluggish with a slight misfire. The misfire would only happend until the vehicle reached operating temp. I changed the fuel filter, noticed brown gas coming our of the lines/ filter. Pump all gas out of tank, gas came out clean. Vehicle ran fine in the test drive.  Next morning, Tahoe wouldnt start. It would crank over fine, but would hit/miss a few times. Now vehicle wont fire at all. Ive changed the plugs, new electronic ignition module, checked for moisture in distributor cap. Fuel pump is pumping gas into the engine/ all plugs getting spark. I dont know where to go from here. My only other idea is that the engine has jumped time somehow. Anyone have a suggestions?

Answer
HI DUKE.YOU MAYBE CORRECT ON THE TIMING. BUT, HOW ARE YOU CHECKING FUEL PRESSURE ?? WE HAVE REPLACED MANY FUEL PUMPS..ARE YOU JUST PUSHING DOWN ON THE FUEL RAIL SHRADER VALVE AND YOU SEE GAS AT THIS POINT AND ASSUMING THAT YOU HAVE FUEL PRESSURE ???? THIS MAYBE RESIDUAL PRESSURE ONLY [[WILL FOOL YOU ALL THE TIME]]] OR ARE YOU USING A PRESSURE GAUGE ?? IF YOU ARE NOT USING A GAUGE WOULD LIKE YOU TO PRESS DOWN ON THE SHARDER VALVE ON THE FUEL RAIL AND HAVE SOMEONE CRANK THE ENG OVER,YOU SHOULD HAVE FUEL THE [[ENTIRE TIME THE ENGINE CRANKS,]]]TRY 5 TO 8 SECONDS OR SO. IF NOT TIME FOR A NEW PUMP UNLESS ELECTRICAL ISSUES. IF YOU DONT WONT TO DO THAT GET SOME STARTING FLUID AND SPRAY IT DOWN THE THROTTLE BODY WHILE SOMEONE CRANKS IT OVER. SEE IF IT WILL START LIKE THIS. IF SO PUMP IS BAD..THIS IS JUST A TEST DO NOT KEEP DOING THIS. IF YOU DID USE A GAUGE CK FOR PULSE AT THE INJECTOR WHILE CRANKING THE ENG OVER..NO PULSE,, BAD PCM TO OPEN THE FUEL INJ. LET ME KNOW,GET BACK TO ME..TOM.