whee do i start I checked the fuel pump fuse and it sounds like thefuel pump stars when you turn on the key but the gas is not getting to the throttle body.
Fuel Filter ever been replaced?
Do you have a fuel pressure gauge?
What year is the truck and which motor does it have in it? Do you have a crank signal? Does the tach jump when you crank the engine? Do you have throttle body injection, multipoint injection, or central fuel injection? Unless this truck is 1992 or older, you won’t see the gas or the fuel system,at all without some disassembly. Most of the newer Blazers had central fuel injection. The injector unit is inside the intake plenum. They usually go bad by leaking and causing an extremely rich condition, but they can also fail.
1999 chevy blazer 4.3 dont no where the fuel filter is because it has a throttle body.
also motor will fire when you put gas inthe throttle body.
You need to check the fuel pressure.
Your engine has the Central Port Fuel Injection system. This fuel injection system has a central fuel injector called the spider assembly. Off this central injector are tubes that go to each cylinder. At the end of these tubes are what are called poppet valves. These poppet valves are forced open by the fuel pressure to inject gas into each cylinder. If the fuel pressure is too low these poppet valves won’t open, thereby no gas enters the engine.
If the fuel pressure is below 63 PSI, the poppet valves won’t open.