Engine surges at higher rpm when cold

[S10Husky]

My problem is with the engine surging when it is cold only when I accelerate and maintain any constant RPM above idle in park. At idle it does not surge. After the engine is warm the problem goes away.I just bought my 2000 S10 with 81,000 miles about 3 weeks ago. It has a 2.2L 4 cyl. vin 4 engine and an automatic 4L60E. I replaced the original spark plugs with new AC platinum plugs and the original plug wires with Nascar Select Borg Warner wires. I also replaced the original fuel filter and installed a new K&N filter. Changed the engine and transmission oils and filters. Took off IAC valve and cleaned off carbon and cleaned throttle body also.When I took off the old spark plugs I noticed plugs # 1 and 4 had ash deposits. I took off both of the ignition coils and found them have the same amount of resistance and being within specs. I'm not sure if this has anything to do with the surge problem above. I also checked for codes with a scanner. It has none. I would appreciate some feedback. Thanks.