Just got this 82 720 and have done everything I can to make it happy. This time around flushed the complete fuel system, new pump, new filters etc.. now it's running worse than when I started. WTF... Any ideas on what to look for?

Also I should probably mention that it's hard starting, like it won't start without pressing on the gas pedal. Then it won't idle I have to keep my foot on the gas pedal and give it gas until in decides to warm up a bit. Then it will idle high and backfire a bit. It also backfire and pops while driving and during deceleration...