My 97 Blazer 4.3 will not start unless i dump fuel under the hood, and after its running it works great, but if I let it sit more than 30 minutes sometimes less, it wont start again, it will start right back up as long as it hasnt been too long after it was running, I have a new fuel pump and fuel filter and distributer cap all put on, if anyone can help, let me know, thanks, [email protected]

Have you replaced the coil?

I had a 1997 s10 4*4 with the 2.8 v6.
mine do that I had to pull the gas tank replace fuel filter plus had to take undo the line from the intake and blow air thru it. Make sure all u're filter are replaced and y u have the tank down replace the fuel pump. I hope this helps u

Could be the fuel pump is not providing the proper fuel pressure !
Fuel psi less than 50 psi no start GM CPI Vortec

this code indicates multiple miss fire,which is not just one cylinder doing it.if this motor has a vortec motor in it the problem could be the injectors not operating properly or the lines to the injectors may be leaking into the intake causing a rich condition.it could be the egr valve stuck open just a bit causing a vacume leak and rough running.it could even be a problem with the pickup coil in the distributer or a cracked magnet.the ignition module could also cause the problem.

could be the fuel pressure regulator...

check the BYPASS valve is the one inyect fuel into the imtake manifold to start thats it

Is it a vortec engine if it is your fuel injector may be the problem. Chevy ran one injector on the vortech engine it is under the upper intake manifold, it has 6 plastic hoses running to each cylinder under the manifold. if one of these hoses are leaking its dumping raw fuel into the manifold during hot soak. that fuel is getting picked up by intake air when trying to start. and flooding it out hence hard to start. gasoline evaporates rather quick so what fuel was in the manifold when you park for the night has evaporated by the next morning so no raw fuel for intake air to pick up easy start. Seen this problem many times. pretty easy fix but a bit pricey around $200

Check the followings:
1. Pressure Switch connection - under front right hand side near lips.
2. Thermostat Switch connection - at the dryer under the hood
3. Retrun Valve maybe blocked - in the cooling pipe from the compressor
4. Cooling Thermostat in the compressor itself.

bad throttle body or injector,

sound like your fuel pump have your fuel pressure and fuel fuel volume tested.sound like your not getting enough fuel.