I've got a 1991 Firebird with the 3.1 V-6 and in the mornings I have two problems that are probably related. First problem is that it has a really hard time starting. Sometimes it will start and sputter and eventually idle up and then sometimes it starts, stutters, then dies and when I try it the 2nd time it starts right up and idles. The 2nd problem is that after I get it started and I take off (engine still not up to operating temp), it hesitates before accelerating and then each time it shifts it hesitates before accelerating again.

The car only does this after it has set overnight or after it sits from 8-5 while I'm at work. If I drive it to the store or gas station and it gets up to normal operating temps, when I come back out, it fires up lickity split and the acceleration hesitation disappears once it's up to normal operating temp as well.

I've changed the plug wires, cap, and rotor. Plugs look Ok but I will be changing those soon as well. Air filter is a K&N and is clean, installed new in the last couple weeks. One thing that I can think of that I haven't changed yet but will be is the O2 sensor. Can you guys think of anything else that I need to check? Could it be the EGR or the TPS? Maybe something else I'm not thinking of.....

Any help with this would be greatly appreciated. TIA!

 

check the timing recently..?