1998 Silverado 350 Vortec won't start when its cold.i hear the fuel pump running, and tried numerous times to start it, finally gave it one shot of starting fluid and it fired right up. Once it runs for a while and gets warm it will start right up. What could this be? Already Tried: fuel pump 6 months old, injectors one year old, fuel filter is new.
Couple of things it could be. 1) Needs new spark plugs (extremely common)
2) IAC (Idle Air Control) is sticking and will need to be replaced. If you press gas pedal about 1/4 way down and it starts , then the IAC needs to be replaced.
3) Throttle body is dirty and is restricting air flow