93 525i Loud Knocking & Won't Stay Running

[raakevin]

I have been trying to fix this car for a month now and it is one thing after another. Probably just too many miles on it I suppose. Car started to die rolling into driveway and have not been able to keep it running since. I replaced the fuel pump thinking it was not getting enough fuel because the only way to keep the car running is to hold the accelerator nearly to the floor. The car then shakes and makes a loud knocking noise intermittently from the engine. This also draws significant power from the battery because each time I try to fix something and we troubleshoot with it running it drains. Then I go charge it at O'Reilly's and we start all over again. I do not have the money to have it towed to a shop to have the computer read so I am hoping someone is familiar with the specific problem and can give me a suggestion on something to try.