fuel system problem

I gave my 450SL 79 to the machanic to do some minor work. By mistake the the car ran out of gas. Eever since then the car would not run properly. It runs as if it was running on 6 cyliders. Here is what I did. I changed the fuel pump, filter, changed the filter in the gas tank. I blew out the fuel hoses, cleaned the injectors. Also just had a new tune up. :screwy: I beleive it's something small because when the car is idleing rough and I put a little gas into the manafol she levels out perfectly. So the engine is not getting enough gas. What other things should I do to find the problem. No one here can figure this one out. Help!

Check vacuum houses. Had a similar problem with my 91 500sl turned out to be a vacuum hose that had a crack in it.

I can't remember, is this electrionic fuel injection or is it CIS injection?
Ether way, is it running on 6 cylinders? With insolated gloves pull each of the plug wires off at each cylinder, one at a time, pay attention to how the engine rpms change. This will help you find out what cylinder is not working correctly.