My car (1993 subaru impreza) hesitates and sputters when it's raining out. It will hesitate, and then as the engine reaches around 3000 rpm, it will wake up and lurch forward with full power. As it warms up, after about 5 minutes of driving, the problem goes away. Up to this point, I haven't really done anything other than changing my own oil and some minor cooling system repair work. My question is: is this a difficult undertaking; given what a distributor cap is, it doesn't seem all that complicated. Is there any issue I will run into if I try and go about fixing this myself?