Hey guy's, I have a 1985 ram 50 with the 2.0 liter and it has been sitting in the driveway as I am working on finishing my workshop so I start it about once a week. When I start it, it starts right up without hesitation but after it sits and runs it seems to run rougher and I can smell rotten exhaust. If I shut it off and restart it it takes a couple of seconds to restart. I have a full tank of fresh gas and some seafoam additive in it. I have put new plugs and wires (ngk) and cap and rotor. Any ideas of whats going on and what I can check. Thanks in advance.