I've been having this problem for awhile now. In the summer time when it is really hot it is a lot worse than in the winter when I hardly notice it only every now and then.

The problem:

During start up , the car would idle fine for about a minute and then would expierience something like when your being choked. The rpm's would be jumping up & down between maybe 300 to 550 rpm's sputtering with a rich smell coming out the exhaust. After about 25 seconds of doing this the choking would be freed up , rpm's jump a **** a hair past 1,000 then drop down back to normal idling just fine.

Also if I dont wait for the erratic adle to pass and just drive off , I would lose some power upon acceleration never letting off the gas then would just free up surging forward. After driving for a minute or two problem is gone.

I cant figure this problem out cause there is no check engine light appearing where I can just find the code.

Here is a list of what I've done so far:

New pcv
new plugs
1,000 mile old distributer cap ( had an extra)
Timing belt & the rest of the belts changed at 120,000 (currently have 142,000)
Fuel filter changed every 30,000
new sparkplug wires from 10,000 miles ago (NGK blue)
Sea foamed (gas tank , crankcase , & throttle body)
Fuel injector cleaner added to a tank before every oil change
Unplugged the IAC valve and the idle dropped like it was supposed to.( not sure if that really means anything)
Jumped the wires at the ecm for the IAC valve and it clicked. ( good )
Checked if the IAC valve is getting power. ( good )

I cant think of anything else to do. If anyone has any insight to what the problem is please HELP!! TIA.