Well I have a miss in my engine when it's cold, it seems to start fine, doesn't feel like it's missing at idle but you bring it between 1k-2k rpm it's got a dead miss, almost a stumbling miss. It does this miss for the whole first drive evey day but as soon as I shut it off, and can start it up the miss is gone, I have money now to figure out the problem so I need some help. I have done the following within 1 month: new plugs/wires/cap/button, coil is newer. I did pull the map sensor plug just to make the computer throw the engine into an open loop, and the miss is barely noticeable then.I have no check engine lights whatsoever and thats why I'm here looking for advice. Anybody have this problem too?

 

I am assuming by your name that it is a 1998. I will also assume it has a 4.3. I would start by getting someone to scan it for any stored codes that it may have even without a check engine light.
It could be something like an injector... leaky fuel pressure regulator... condensation in distributor cap... etc...

 

I had this happen on my 97 Blazer awhile back. Our Blazer started a miss once in awhile with no codes. We continued to drive it for a few weeks missing every so often. Mainly under a load (IE: pulling a hill). Well finally it threw a check engine light & the problem turned out to be a plug wire burned off at the plug under the boot & these were wires that were less then a year old. So first I would check all the wires to be sure they are OK. even if they are new. I have seen NEW wires go bad quickly.