Fuel & Electrical

Recently had a strong fuel order in the cab of a 1994 Chevy S-10 - 2.2L. Took it to a certified mech. who replaced plugs, plug wires, fuel injectors and manifold gaskets, did a tune up etc. It ran okay for a few days then began runing rough and hesitating. Took it back and they did some minor adjustments. After a few days it started running rough again, hesitating and stalled a couple of times. It sat for about 4 days while we used another vehicle before taking the S-10 back again. Made arrangements to take it back again and it was really hard to start, ran really rough and stalled twice before getting to the garage. Arriving at the repair shop there was smoke coming out of the engine compartment. Lifted the hood and the wires connected to the altenator were smoking. Could this be connected to the other repairs? If so, how and if not any suggestions as what caused this. We've put nearly $1800 into these most recent repairs. HELLLLLLLLLLLLLPPP!