Why won't my car start???

I have a 2002 Mitsubishi Eclipse, 4 cylinder, manual transmission. Last Thursday it just stopped running, no check engine light, nothing. It ran perfectly then I went to turn it back on and it would act like it wanted to turn over, but nothing. I got it to run the next morning and I took it to a shop. They replaced the cam position sensor, valve cover gasket, spark plug and wires. It ran beautifully- sat unused over the weekend and Tuesday morning I go to start it- it turns over, chugs then stalls. It would only stay on if I gave it gas and the check engine light came on. I got it running again and took it back to the same shop- who then told me it needed a new battery. So they replaced the battery and it ran beautifully. I try to start it this morning and it is doing the same thing, only with no check engine light on. Once I get the car running, it runs like a champ. It is just getting the car to start and keep it running for the first minute