your timing could be off causing it to advance or retard the timing when it doesnt need to, does it run well once it is started, also be careful with backfires if it backfires part way through the compression stroke you can damage your piston and connecting rod.
engine backfire during cranking.
No, backfire is usually caused by park plug wires that are installed incorrectly or an engine that is out of time. Fuel filter and pump will not cause backfire.
YES. Bad fuel pump pressure can cause that problem too.
Impossible to predict. One thing that can cause the fuel pump to fail prematurely is a partially clogged fuel filter. Change the fuel filter every 50,000 miles if it is replaceable.
ac evaporator drain may be stopped up causing it to retain moister which will cause mold. possible cabin air filter needs to be changed
There are a few issues that can cause a 2006 Chevy Suburban to not start on first crank. These can include a dead or drained battery, problems with the fuel system, or issues with the starter.
It can be eithier plug wires crossed or burned valves. Have it checked out.
Bad switch.
clogged fuel filter or faulty fuel pump or shorting wires for pump check wires first then filter
Incorrect Timing Can Cause Backfire.
burned out bulb, blown fuse, wiring
check ecm fuse