1998 Honda Accord Honda starting rough and loses power uphi

4cyln Honda upon starting runs rough like only 3 cylinders are firing and then smoothes out after rev or 10 seconds or so. I back out of driveway and then proceed up a short hill climb at about 3% grade for about 2 blocks. The car accelerates and then when climbing hill loses power and then all of a sudden gains power again and then proceeds to bog down again and then regains power. Once the car is warm it doesn't do this. I have fully tuned the car with new Spark plugs and wires, rotor and cap, air filter. Just had the computer chip for fuel mixture replaced and a valve that kicks in another set of rocker arms when you push the pedal down and need more acceleration. Both a local repair shop and Dealer can't figure this one out and I am very frustrated. Can you help.

Thanks,

Dennis