I have a 98 honda accord and when it has been sitting out in the rain or a wet day for a while (a few hours or more), it takes it a really long time to start. It will crank like it's trying to start, but it takes a few minutes of doing this before it finally will shake and sputter to start. Once it does start, it sometimes dies when I press on the accelerator (normally only for the first few minutes of driving). My mechanic reaplaced the ignition switch, cap, rotor, wires, and spark plugs. This worked for a bit over a year (I had absolutely no problems during this time), but now the problem is back again. He seems to think that it would not be the cap rotor or wires as he said he used good parts which should last years. I have been told this could be a fuel injector, fuel pump, or fuel pump relay problem; however, this can cost upwards of 600 dollars to replace. I don't mind spending this much but how can I be sure this is the problem?

 

This sounds like the infamous main relay problem.

 

Test the ignition coil.Is the problem more pronounced when you going uphill?Make sure there is no humidity or oil under the cap.And definately check the relay.

 

Agree that this "sounds" like the relay.....To verify I would test/inspect the relay or wait until the next time the "situation" is right and watch for a few things.

Turn the key to on, watch the CEL - should come on (hear fuel pump run) and then go off after ~3 seconds.....if light does not go off then you are pretty sure the main relay os the issue.