plasticweld

I am getting air bubbles in my fuel, I have a see through filter before the spin on,that shows air in the system. I am not familiar with the Benzs enough to know if this is the cause of the car running rough. I would assume like any diesel with this type of injector system that it can not properly run with air in the fuel. I am making some assumptions as I have no manual. The fuel pump in the tank maybe weak and the air bubbles I see may be caused by vacuum, there is a a air leak in the line somewhere that will suck air but not leak fuel. I have bleed the system of all air,and there is a steady supply of new air. The car runs well once it is warm and I am wondering if I need to take the car to someone to have a leak down test done to test the compression, the car maybe in poor enough shape where it is a compression problem and not a fuel problem. The car has 320,000 miles on it, I have had it for 2 years and this is the first time it has ever given me a problem, I need to spend money on the exhaust system and was planning on painting in the next couple of weeks but would like to take care of the issue of how it is running before moving foreward.. New to the board I hope this is a common problem, Thanks in advance..Bob

SSnelling

The filter you mention as "see through" should be the pre-filter. When you refer to air bubbles, are you describing one large bubble that rests at the top portion of the pre-filter as it is situated in your vehicle? If so, can you observe this large bubble pulsing at a steady rate (idle conditions)?

Have you ever used diesel purge as a direct (clear jar with two holes in the cover, 14" piece of fuel line, a couple of clamps) means of cleaning your injectors? If not, search the web for the quite simple procedure. Lubro Moly Diesel Purge can be found from a numbe of sources.

Best of luck.
Steve

plasticweld

Steve the air bubbles are coming into the pre filter at a steady rate, I have tried using the manual pump to bleed the injector body and the lines. I have also let the car run and crack each injector to bleed off the air. the car runs fine at highway speed like there is no air problem, actually with the new injectors it has never run better, there is a flutter to the engine at low revs-no load, under load seem to be fine. there is a stead stream of air in my return lines which are clear when the car is cold when it has been run for a time the air dissipates.. Thanks for taking the time to answer..Bob