Had a friend change my plugs, wires, cap and rotor in 89 305 TPI. I ran good before I brought it to him, after he changed them it was running horrible. I drove it a few miles turned around to bring it back to him. When I opened the hood there was smoke it looked like it was coming from the distributor. He re gapped the plugs and it ran a lot better but still has a rough idle and sometimes eratic on a cold start up. Could this be just a vacuum leak or should I have someone check or possibly replace the cap and rotor and ICM in case of any damage. Thanks