Starting/running issues with a 2002 Volvo S40 1.9t

by rwehling13 - 10/7/08 9:30 AM

My car started having start issues back in May. I would crank for a few seconds before it would finally turn over and start. I replaced the fuel filter, but it has not corrected the problem. My next step was to replace the fuel pump, but drove it to work this morning, got in it to leave for lunch and the battery was dead. I went to jump the car and noticed that the neg. battery cable was really corroded, and I also noticed that the car had the original Volvo battery in it. Could these issues all stem from a week battery and poor contact? It was also cooler this morning than it had been so the battery could have also been weak because of this. I was able to get the car started by jumping it, but could not take my foot off the gas peddle because the car would die. When I got home the alternator had charged the battery enough to where the car would crank, but the only way I could get it started was to push on the gas and leave my foot on the peddle to keep it idled up. I can hear the fuel pump come on, but it is making a high pitched sound. I am now at at a loss, is this due to the batter, the fuel pump, or the fuel pressure regulator, or a faulty O2 sensor? The check engine light has been on for over a year. It originally came on when the car had 45K miles on it and the car now has 75K miles on it. Any suggestions on my best approach of attack?