I have a 93 s10blazer 4.3 vortec 4x4 that wont start. my fuel pump is working i replaced the ignition module, ignition coil, plugs n wires r good, distributor cap and rotar button. idk what it could be

vacuum lines

Pull off the coil ignition cable at the distributor and check for spark coming out of coil when cranking engine over. Use a heavy rag or glove to hold the wire 1/4 inch from a metal ground. Should see a strong blue spark when cranking to verify ignition is good. If no spark, check for battery voltage to coil on the coil primary. If you have current to the coil, suspect a bad coil, ignition module, crank position sensor, or cam position sensor, or pcm. The coil, ignition module, and sensors can be tested before replacing.

Right at the coil is the ICM (ignition control module) These wire are known for poor male to female connection have some one crank it and you wiggle it to make contact,Also where the battery is is a power ground if that ground is corroded it will give code P1355.

So, do you hear the pump buzz on, when key is on? If that's good, then check your ignition circuit: check for spark at a plug. Use insulated pliers, hold end of plug wire 1/4 inch form engine bolt or ground source. When cranked, you should see a bright blue spark. Yes? Try another plug wire, too. No? Try another plug wire. If you have NO spark, could be your coil, coil pack, crank position sensor, ignition module. I would recommend using a diagnostic flow-chart to go through the ignition circuit. That way, you are not replacing unecessary parts_Expensive! Of course, if you have spark at plugs, your ignition circuit is good! Then you have to look further, like your injector circuit. Good luck.

Have you checked your fuel pressure? Can you hear your fuel pump buzzing. Remove your gas cap and have a helper turn the key to the run position while you have your ear close to the open tank. If you don't hear anything you have a fuel related issue. Even if you hear the pump buzzing you need to check the fuel pressure as it may not be making enough pressure. If no buzz you may have a bad fuel pump, pump relay, or wiring problem to the pump. That is where I would start.

What size engine? Sounds like crank sensor or ignition module.

have you checked the fuel pump relay?

My 98 sonoma would not start if humid and about 70F. There was also no fire when acting up. Finally found a bad connection on the hall pickup sensor from the distributor. I put ox-guard on the connector pins and plugged it back in - no problems. Took about 2 years and $500 in wasted repairs to find this. Good Luck!

Is it not getting spark or gas? It needs both to run. Both main source. If no spark in any cylinder, then ignition module or crank sensor is likely faulty. If no gas, then fuel pressure regulator or fuel pump or fuel pump relay is bad.

Had the same problem with my '96 Silverado with 350 Vortec. The truck would only crank. It would start if fuel was poured down the throttle body. Could not hear the fuel pump hum. Fuse was good, but could not hear relay click. Relay was good, Did some electrical wiring trouble shooting. Turned out that one of the connectors that clasp onto one of the pins of the fuel pump relay wasn't making a good connection, too loose. I just stuck a peice of wire into the connector and pushed the relay back in. Relay clicked, Truck Started. It's been more than 4 yrs. since I made that McGuyver fix. Still firing.