My 89 chevy carpice has been sitting in the carport for about 2 weeks because its been snowing now it is not so I took it for a drive be fore that I check the oil it was low I put some in while I was driving back home I notice my car was shaking while was pushing the gas pedal and when the stop sighs and stop signals it was fine was wondering why it did shake?
Chances are something in the ignition switch is damp from sitting in the snow and then warming up (condensation). If the problem continues, in the dark, start the engine, open the hood and watch for arcing from plug wires, coil, distributor. If none, mist water on the components to see if that changes it. If it only happens under a load, have a helper watch for arcing while you put the vehicle in gear with your foot on the brake and the parking brake on. WHile your foot is firmly on the brake, give it gas to cause it to miss and have a helper (from the side of the vehicle) watch for arcing.