1995 BMW 325i M3 won't start

[aussie]

I have a 1995 model BMW 325i which has had trouble starting for some time. It usually starts first go but then after driving it for a while, if I stopped and then tried to re-start the car, it would take several goes until it started. This went on for about a year or so, I had two mechanics look at it, but they couldn't figure out the problem. I didn't worry too much because it always started eventually.

A couple of weeks a go it refused to start at all. I had a feeling that it was the computer because I tested the fuel pump and it wasn't getting power. So I took the computer out and noticed that there was some corrosion on one of the solder joints. I also tested all the components with a multi meter and noticed that 2 resisters and a transister were not giving me a reading. I found a local technician who manufactured and repaired circuit boards and paid him to replace the three components and resolder the dry joint. I put the computer back into the car and it started first go. I started it about 3 times and let it idle for a while, but I didn't drive it or rev the motor.

The next day I went to start it again but it would not start. I noticed that the battery wasn't fully charged so I presumed this was the problem and left it on the charger overnight. The battery is now fully charged and I have tested the fuel pump (I have power to the fuel pump), but it still won't start. The motor is turning over but it sounds like there is no compression. Can anybody help?