Rough running 94 Chevy Pickup

[BigSwen]

Hi guys...we have been chasing our tails here. My son's basic transportation is a 94 Chevy 1/2 ton 2wd with the V6 engine and Auto Trans. It developed a tendency to stall out when you put it in gear, mostly when the engine is cold. It starts beautifully, but doesn't maintain the high idle and then will die. Restart it and rev it up a little and it will eventually behave better. It has a hesitation while accelerating as well. We have replaced the cap and rotor. Plugs aren't very old, had the Throttle body rebuilt and the thermostat and the idle air control valve was replaced too. It has 10 psi from the fuel pump and has a new fuel filter. The tranny upshifts from 2nd to 3rd a little hard, but that shouldn't affect the cold start. When you step on the accelerator while driving, it "bogs down" and then catches up and runs better. So, suggestions on the cold start issue and ideas on the bog down? Could the Catalytic converter be an issue???'

Thanks!

Mark

[Macgyver55]

I would check for a sticking EGR valve or other possible vacuum leak.

[Jeremy airjer W]

My first thought was weak spark?