Just bought 1989 740 GL in February, it was running great then....
We put fuel cleaner in it, and a few weeks later it would not start at all. We found that the pink wire to the in-line fuel pump had burnt. After fixing this the idle was rough. At start up sometimes it idles correctly, sometimes it goes inbetween 1000 and 500, sometimes dying. When we finally get it going there is a hesitation when trying to accelerate, especially at speeds 40mph and under, and when stopping it dies completely so I have to drive home with one foot on gas and one on brake. We have taken it to a mechanic and a few days after taking it home it acts up again. So far a vacuum leak at the intake boot has been fixed along with throttle body and tp switch being cleaned, mass air flow sensor replaced, and air intake tube replaced. Any suggestions? I love the car and don't want to give up on her. Please help!!