Honda Prelude startup problems?

On random instances my '98 Prelude sputters and sounds like it is running on half its cylinders for about three five seconds right after I start it. If I rev it once or twice it'll break loose and smooth out and will run perfectly good untill I turn it off and attempt starting it again. It will not sputter or miss or anything while I am driving, while pulling a hill.

Today I replaced the plug wires, cleaned the plugs and EGR valve.and its still acting up.

Anyone have any ideas?

the valve modification is important on that car to maximize engine performance and fuel economy. Chances are that the valves are out of modification and because of that you have a lean mixture at start up that causes the spitting and sputtering.
The 1st thing I could recommend is to have the valves adjusted. On that car the valves should be adjusted every 30k.

You should also check the throttle body to clean out any carbon that can be restricting the idle air passages. Carbon build up is quite common on older cars and if the idle passages are constrained there will not be enough air bypassing the idle to let the engine to runs smoothly under cold start enrichment.

if the conditon remains unchanged after the valve modification and throttle body cleaning, the other item could be the coolant temperature sensor. That sensor 'tells' the computer that the engine is cold and that signal causes the cold start enrichment. If the sensor signal is not right, the fuel mixture on the cold engine will not be right.

the valve modification is the most probably a because, then the carbon build up and lastely the coolant sensor.

hope that assists