Dying Trouble

I have a 92-93 Chevy S-10 Tahoe Blazer, and sometimes it runs fine. But most of the time I will be driving down the road and my truck will kind of stutter and eventually dies. The check engine light always comes on, and sometimes the battery light and check gages light will come on. It will start back up and then die again. Sometimes it won't start back up until you let it sit for a while. We've changed spark plugs, fuel filter, and the fuel injector. I don't know if this would have anything to do with it, but our reverse is out in our transmission, and the oil leaks constantly- I have to put at least 3 quarts of oil in every two weeks. We've checked the battery, and the altenator was unplugged one time when the truck wouldn't start. We have tried everything we can think of, and we've asked several mechanics but no one can figure out what's wrong with it. Please help me and tell me you know what's wrong with it.
Sincerely,
Trouble