Chevy k1500 5.7 v8 wont start

when you put distributor back in most likely off a tooth

When you changed the distributor did it go in the right way sometimes people put it in 180 degrees around as it will drop right in then also take a look at the rotors position when you are at the proper firing position for 1 and check it otherwise it seems like a walk down as in going backwards on all your steps to see if its right

very good but did you check that the no1 piston was on tdc firing before you replaced the distributor . You may be 180degrees out on the firing order.

Check the throttle position sensor (TPS) and system vacuum.

try changing out your throttle position sensor

Your 4.9 has a distributor, correct? If so, it does not have a crank sensor, per se, it has a hall effect sensor in the base of the distributor, also called a coil pickup, just below the rotor. It has a harness that goes through the distributer housing.cap and plugs into a harness, and is pretty easy to replace.

I WOULD CHECK IGNITION FUSE TO SEE IF POWER GOING TO COILS AND IGNITION MODULE. REPLACE DISTRIBUTOR CAP AND ROTOR.HAVE IGNITION TIMING CHECK.DISTRIBUTOR CAN SLOWLY WORK A LOOSE JUST A LITTLE TO THROW OFF IGNITION TIMING SO PLUGS WONT GET NO SPARK.

Turn on the key and listen by the fuel tank for the fuel pump to hum. A common problem is low fuel pressure. It will build pressure when the key is turned, use that fuel, and then the pressure drops. Kind of like when you're using a squirt gun that's getting empty.

the back firing sounds like to me that the spark plug wires are not in right position on distributor cap, firing on wrong cylinder, did you remove distributor or distributor cap?

Inspect Wireset Damaged, worn, or deteriorating spark plug or coil wire(s). in this list u will find a answer to ur problem Shaun 2 Inspect Spark Plug Fouled, damaged or broken spark plug(s). 3 Inspect Fuel Filter Clogged or dirty fuel filter 4 Inspect Distributor Worn, loose or incorrectly adjusted distributor. 5 Inspect Distributor Cap Loose or cracked distributor cap 6 Inspect Distributor Cap And Rotor Kit Loose, cracked, or worn distributor cap and ignition rotor. 7 Inspect PCV Valve Plugged or damaged pcv valve. 8 Inspect Air Filter Restricted or clogged air filter. 9 Inspect Catalytic Converter Clogged, damaged, defective or faulty catalytic converter. 10 Inspect Automatic Transmission Improperly adjusted kickdown cable adjustment or internal transmission problems. 11 Inspect Fuel Pump Improperly functioning fuel pump or circuits. 12 Inspect MAP Sensor Improperly connected or faulty m.a.p. sensor. 13 Inspect Mass Air Flow Sensor Improperly connected or faulty mass air flow sensor. 14 Inspect Throttle Position Sensor Faulty throttle position sensor or throttle position sensor circuit. 15 Inspect Timing Specification Incorrectly adjusted engine timing. 16 Inspect Fuel System Pressure Incorrect fuel pressure being delivered to carburetor or fuel injection system.