Pagoda SL Group
W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: Wray on April 03, 2025, 19:00:58
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Is it necessary to bleed the fuel injection system on a 1969 280SL when it has been dry. Had crud in the fuel filter bowl likely dried varnish from old fuel, cleaned the canister and changed the fuel filter. Drained the tank for boroscope inspection, looked fine. Added 4 gallons of gas with Seafoam and a bit of marvel mystery oil. Now it won’t fire. Prior the car started with no touch of gas pedal on a couple of tries. Thanks for any thoughts
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In the past, bleeding the system solved my no start issues after removing the fuel lines to pull the head. You may consider cleaning the hard fuel lines while you’re at it. A 17mm crowfoot wrench is very useful for that job. I believe you can use lacquer thinner to clean the hard fuel lines, but I’d verify that before trying it.
You can bleed the lines pretty easily by loosening the injector nuts that connect the lines to the injector, turning the key to run the fuel pump without cranking the engine, and tightening the nuts to about 21ft/lbs when you’re done. Sometimes they’ll need a bit more torque than that to seal, just go slowly because you’ll twist the lines or strip the thread very easily if you use too much force. I’d also have something at the injector end of the line when running the pump to catch the fuel. Perhaps a small cup instead of a rag in case she wants to go up in flames.
You can bleed the fuel filter canister by loosening the small slotted screw that faces towards the radiator and running by the pump. Be careful here too as you’ll spray fuel all over the engine bay if you run the pump for too long or loosen the bleeding screw too much.
My memory’s not the best on this particular job, but those procedures should work for you. Good luck!
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After letting the fuel pump run and pumping the gas pedal the car started. Ran somewhat roughly. Cleaned and regapped the plugs. Runs very evenly now. Next step are small road trips in ever increasing distance to validate clean fuel delivery. May get lucky and not have to replace the tank.
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Nice! Fouled plugs can definitely trick you into thinking something else needs work - I’ve been there before haha. You should be able to replace the flower pot fuel screen in the tank provided that the tank is clean. Replacement tanks are about $650 if I remember correctly from when I purchased mine. Enjoy your car!