[Geosangel]

I just put in a new alternator last night, because of the slow start/no start issues. It fired right up, and quickly. Let it sit overnight, it fired right up this morning, no problem. Got to work, let it sit for 5 hours. Went out to leave, and, it cranks, but would not catch. A student opens the hood, twists the throttle, has me cranking it, and, it fires right up. At this point he tells me not to shut it off until I get home, gives me a laundry list of items I need to buy (over 2000$ worth), and a host of new problems, which he self diagnosed by just looking at the engine, including telling me that the original factory water pump is still on the car. (Can you tell this by looing at it? I mean, it looks brand new, but I don't know.) 2 hours later, I'm home, and he is calling me, wanting me to sell him my car, or trade mine for his non Porsche. Now I'm sitting here thinking 1 of 2 things: he wants my car badly, or he is being genuine and wanting to help me out. I am at a loss, and my husband is at work freaking out because he has to spend another thousand (or more) on parts, and take more time off work to fix it. (this is my daily driver). I need some serious input here. While I don't have a ton of cash on hand, I do have some, and as weeks come will have enough for maintenance for this car. What I need to know is what could possibly be wrong as to why its intermittently giving me starting problems. I have ordered these things for now, in hopes that it could be something simple: new plugs, a fuel filter, and an air cleaner ( I know the air cleaner isn't the problem, but it needs one badly.) Here is another bit of info: when I start the car and it wont catch, the volt meter drops way down to 10. Other times, it's normal, at 13, and fires right up. Any tips? Thanks...