Fuel pump
 

My mechanical fuel pump went out. Replaced it and still not getting fuel. Help!!

year make model

78 K5 Cheyenne 5.7L

the lobe on the cam could be flat causing it not to pump. also try priming the engine. usually when those lines go dry you have to pour a little gas in the carb to get the engine turning fast enough to pump gas up to the fuel pump.

also other stupid things to think about.
make sure you put the rod in between the cam and fuel pump.
make sure theres gas in the tank, not just a gauge that says theres gas.

you can try bypassing the fuel pump all together with buying a electric pump to temporary put inline to make sure its pullng gas and your carb floats arent stuck or anything like that