I got a 90 300sl that runs half way decent when cold, but when it get hot, it cant get out of its own way. I have replaced plugs, wires and the rotor and cap are three years old. the car is much worse when it is under load, (a/c on or in gear) idles fine and revs in nuetral fine. It feels like a miss, and I noticed when I try to adjust the plug wires, I get different results in how the car runs, but it never runs great. Is there a certain way to run the wires, or should i be looking elsewhere.