My 1989 260E has a weird problem. When it is cold outside (<35F) the car starts great (like always). It runs great in the beginning but as it warms up a little the car will start to hesitate when the gas is applied. It still goes but very slowly. It does this from when the car starts to warm up until right before it is full warmed up. When the car is fully warmed up the problem is totally gone. I plan on doing the cap, rotor and plugs because it it time but is there anything else I should know about. Thanks in advance.