My wife’s son bought a used 96 Chevy pickup
Shows no codes but it misfires and every morning he has to pour gas in the port and put the breather on it before it will start after it starts it is good about starting all day. I put new fuel pump in tank new wires and plugs. and sensors all of them. This one has got me need Help!!!
It sounds like there may be a check valve in the fuel line that is leaking and allowing fuel to run back to the tank when the vehicle isn’t running. The check valve is usually in the fuel pump but perhaps there is a seperate one for this vehicle. Check that out to see if that is the case.
This I think has throttle-body fuel injection. You should be able to look and see if the injectors are spraying fuel in decent quantity on the first start of the day. (Do not put your finger under there to check! The fuel spray can cut you like a razor!)
Not sure if this system also uses a cold-start injector, but if it does, this could be failing.