car sat 4 years. purging old gas?

greetings.

just got a 70 280 sel home that has sat four years with about a 1/4 tank of gas in it and i was wondering what all i should do to the fuel system before trying to start the car.

i am going to drain the tank and put in fresh gas see if i can figuare how to disconnect the fuel lines at the engine and pump fresh gas thru the lines before the old gas hits the injectors.

that's about all that i can think of. (besides cleaning the tank screen and new fuel filter.

anyone have other advice as to what i should do to the fuel system?

thank you jlwggns

[G-Benz]

You can still run the old gas...the octane content isn't what breaks down.

If there is 4 yr. old gas sitting in the carb float bowl, that is where your real potential for problems will lie. Old gas "varnishes" and penetrates jets, butterfly valves, accelerator diaphrams and so forth. If you can get it started at all, I suggest filling up with fresh fuel of course, and probably the highest octane you can find. You did say you had injectors, so it may be a moot issue. My dad has a 71 280 SE and it's a carb unit, so I had to mention this.

I left a VW sitting for 5 years, and ultimately had to rebuild the carbs.

Something else you noted is that it is a 1970. Cars of that era where designed to burn leaded fuel. The lead content served as lubricant to valve seats. Engines designed to burn unleaded are equipped with hardened seats as a result. Over time, your engine will suffer from valve seat recession, requiring a complete valve replacement as a result of prolonged burning of unleaded gasoline.

My same VW motor was rebuilt with hardened stainless steel valves in order to be able to burn unleaded gas.

This post was not meant to scare you, but alert you of potential problems you may encounter...

[Mike Richards]

[QUOTE=G-Benz]You can still run the old gas...the octane content isn't what breaks down.

If this were true, products like STA-BIL wouldn't exist. The gas is flat. Get rid of it.

[Kestas]

G-Benz, are you sure the 70 280SEL can't burn unleaded. My 71 Cutlass specifically states in the owner's manual that it can burn unleaded. I figure if GM had the foresight to design engines for the then upcoming switch to unleaded, Mercedes should have had the same foresight.

[Arthur Dalton]

<>

Someone change the motor ??
SE is injected..

[G-Benz]

Originally Posted by Kestas

G-Benz, are you sure the 70 280SEL can't burn unleaded. My 71 Cutlass specifically states in the owner's manual that it can burn unleaded. I figure if GM had the foresight to design engines for the then upcoming switch to unleaded, Mercedes should have had the same foresight.

Probably true...my Veedub however wasn't equipped to handle unleaded from the factory, so a valve retrofit was in order.

Originally Posted by Arthur Dalton

<>

Someone change the motor ??
SE is injected..

I'm really having a senior moment here! Also true. I was probably staring at the throttle body, not the carb. I'm going on visuals from 30 years ago, and I didn't know a whole lot about engines back then...

(backs out of thread with tail between his legs...)

[Hatterasguy]

I am pretty sure all MB made after the war don't need lead in the gas.

Drain the gas it is shot, don't try to run it you could do a lot of harm.

Also change the oil and shoot some oil into the cylinders defore turning the engine over.

[pentoman]

Don't worry G-Benz, we all get it wrong sometimes!


Russ