1978 240D won't start - air in system? - Mercedes-Benz Forum

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post #1 of 3 (permalink) Old 05-30-2013, 11:00 AM Thread Starter
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Date registered: May 2013
Vehicle: 1978 240D
Location: nashville, tn
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1978 240D won't start - air in system?

I've got a frustrating problem I'm trying to troubleshoot. A few months ago my car was losing power and changing fuel filters didn't help. Took it to the shop and the tank screen was replaced and a new fuel pump was installed. It ran fine for a few weeks and then I'm pretty sure I got bad gas and same problem all over again. Fuel filters were black and full of crud. I drained the tank, changed the tank screen and changed both fuel filters. Now the car will turn over but will not catch. The primary fuel filter is empty no matter how many times I pump the primer. I had the new style primer installed a year or so ago. I have literally pumped 5000 times and nothing changes. The car was starting before I dropped the fuel (just losing power and then quitting) so I'm kind of at a loss. I made sure all connections were tight, hoses look in good condition. So to reiterate: new fuel filters (secondary filled with diesel before installation), new tank screen, new fuel pump and new style primer pump - still apparently air in system. If anyone can give me any further ideas before I get him towed to the shop I would appreciate it. thanks!
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post #2 of 3 (permalink) Old 05-30-2013, 03:03 PM
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If you post in the diesel discussion ares you will get more advice. Have you tried to loosen the hard lines at the injectors and cranking the engine over and inspecting for fuel? Sometime you get so much air in the system, you need to loosen the hard lines to get the air out.
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post #3 of 3 (permalink) Old 05-31-2013, 07:46 AM
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you should always fill the spin on filter before installing .atf or fuel .at top of filter assembly , there is a small hose that goes to injectors , if you could disconnect it and apply vacuum at the filter side , this would draw fuel from tank and fill system .go to a part store and buy a suction gun [ handy to have ] .now when you are done , it will take some cranking , just make sure battery is charged , floor the gas pedal and crank until engine will run .loosening the injectors lines will do nothing , dont .
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