Humidity issues??? normal??

[honciv98ex]

I have a Honda Civic 98 ex. Whenever it gets humid outside or a heavy rainfall, the start is very rough. The engine will turn on depending on how long i've let it sit. I've ruled out battery and engine starter b/c both are fairly new. I think it is condensation build up somewhere ..after i get the car started, it sits a chuggs as if it needs gas, but when i go to give it gas the revs reduce and the car nearly shuts off....after 15min the revs increase and the car sounds normal....after this occurs my engine light will come on for 3days and then turn off

Where should I start looking for the problem??? If anyone can post a link or help me out, thanks in advance

[bluevp00]

Did you check your distributor cap? I know water can get trapped in there sometimes on humid days.

It's really easy to check, just unscrew the 4 screws around it to open it up. There should be a rubber gasket around it, check it for tears or cracks. You may have to disconnect your spark plug wires to get at it, if so, make sure to draw a diagram as to where each wire goes when you re-install it.

[96 civicturbo]

check the IAC, or mass air flow. The IAC has a ball inside of it and it is know to stick in wet or humid weather. But check the distributor,cap and rotor inside first. If any rust looking color is on the rotor inside the cap, then I would replace that first. It is alot cheaper then the IAC assemble