Cars Won't run

My car stopped while someone was driving it. They had my car towed to their home. When I got back into town I tried to get it to start. It wanted to start but it wouldn't. Eventually, I was told to add more gas so I did. Then I pumped the car few times and turned the key and BOOM it started. It shook, it smoked, and it rattled. I figured it needed gas. Half way up the street and at a light the car dies. So I was pushed out of traffic and tried to start the car. Well, the car would start and as soon as it went into gear and you ut your foot on the gas, it stopped. So I was pushed back down the street where my car was parked at my friends. The next day I had it towed to the shop. The mechanic told me this was the 2nd Alero he had this problem with and the first one was "done away" with.
Once my car was hooked up the computer read "misfire" and gave a "P" code but did not pin point the problem so he changed everything he thought it could be, still no luck. Well that wasn't good. So I came home holding on to all hope and looked up a Quad 4 online. I found out what to do when you get that specific "P" code. Took this info to my tech and left. When I returned he had my car purring like a kitten. Come to find out gas was leaking into the oil and the fuel regulator wasn't functioning, when he disconnected the hose to the regulator gas came spurting out. So now I am waiting for him to fix the leak on the new regulator and change my oil, fuel filter, and all of that good stuff, so I can take her home. My Alero and I have driven across country from Seattle to NY and back 3 times. This has been my only “major” problem. When I 1st got my car the driver’s side window malfunctioned, since it has done it again. But I haven’t have engine problems until now and she is 5 years old.