Need help. My '91 GMC Sierra 132K miles is having issues. I've replaced the idle sensor, throttle body gasket, ERG sensor / valve, vacuum lines, plugs, cap, wires, fuel filter and nothing has worked yet. When starting up, the engine idles / surges rough and usually dies the first couple of attempts. After running for 10 - 15 min. at high idle, it smoothes out and runs fine. If it's not warmed up, it feels like it's either flooding out or running to lean. Restarts fine after warmed up. The only thing left is the fuel pump I suppose, am I missing something? (same as previous post, I'm just not a Guest anymore!) Thanks in advance for your advice.