After very heavy rain my 1999 honda accord won't start in the mornings. The car starter and ignition turns over no problem but the engine won't fire. I can hear it spluttering and shaking till it catches. Had this problem in the spring and I changed the HT leads and spark plugs and car ran OK but the problem has come back this winter. If I pump the gas peddle when starting the engine doesn't like it and it cuts. Seems to catch better if I lay off the gas peddle. But I can get to work leave the car for eight hours and it starts okay, its only a morning thing in very wet weather. Any advise on what to fix.