Fueling issue!! Halp!!

[Louiehenry]

Hey guys! I haven't been on this forum in a couple years, but I have a 1971 280sl my dad bought new in 71 and it only has 10k miles on it, but while driving it down the interstate today, I noticed it does a sort of lunging motion. It's very subtle, but it almost feels like it's pulsing at about 3000 to 3500 rpm
If you stay in the throttle it goes away, but if you're just staying at a steady speed it stays. I figured I'd go through the fuel system when I did my annual service (which is today) and picked up the fuel filter for it, now I'm curious as to where the fuel filter is on this car as well! So I guess it's a 2 question post.
1. what could be causing the surging
2. Where does the fuel filter go on these, so I can replace it!
Thanks guys! Look forward to getting back on the boards and talking to y'all again!

[Cees Klumper]

Hi again and welcome back.

Sounds like you might want to invest in a Haynes or similar manual. The fuel filter sits on the driver's side of the engine, about halfway in its own aluminum container. Careful as you unbolt it and remove the canister, as fuel will spill out.
The surging is a new phenomenon for me, but it sounds like fuel deliivery could well be a possible cause. There's tons of posts here about fuel deliver issues, such as contamination in the fuel tank (search for 'flower pot' courtesy of the Benz Dr up in the Great White North) or in the small filter screen located in the fuel pump at the back of the car.
Good luck with sorting it out and keep us posted.

[kampala]

see attached photo from tech manual.   The main fuel filter is in the canister on the driver side of the engine (LHD) towards the front next to the dipstick.   Circled area with arrows. 

[Jonny B]

Having the Haynes (or the BBB etc.) will be a huge help. As Oz states, the "main" fuel filter is at the engine as the photo shows. There are two other filters in the fuel system, one at the inlet to the pump and one in the tank where the fuel is drawn from.

[guyke]

does nowbody have a haynes on pdf so that it could be downloaded , it would saving money to a lot of people , 

[hkollan]

does nowbody have a haynes on pdf so that it could be downloaded , it would saving money to a lot of people ,

Yeah, that would probably make the Haynes guys happy. Assuming they are
in business just to kill time and have fun.

[guyke]

http://www.sls-hh-shop.de/katalog/english/Mercedes_Benz_230SL_250SL_280SL_Pagoda_R113_W113.pdf

[Dave H]

Welcome back Louis.

Did you ever manage to find a project car , i remember you were on the look out a couple of years ago.

Dave
 

[Mechudo62]

If you plan on long term ownership of your 280SL, the purchase of the BBB on eBay is well worth the investment. It will help you and/or your mechanic perform maintenance procedures to keep your Pagoda running smoothly and efficiently. The service and warranty booklet that originally came with your car describes recommended maintenance in detail, if you still have it, and this site also has a full description for recommissioning a Pagoda after purchase.

Besides the fuel filter, you may want to check the oil filter, air filter, spark plugs, condenser and points, fuel pump air filter and WRD thermostat and ignition wires. All these items interact with each other and need to be in perfect tune for the engine to run correctly. Believe me, every little detail has an influence on the way the engine works... good luck!

[menesesjesse]

I had a similar issue with my 230. You need to ensure the fuel lines are clear.  If the return line is plugged or blocked it will cause a drivability issue.  Also I would suggest to get a upgraded ignition setup.  Points and float can cause this to occur also. Hope this helps

[ja17]

Yes Louie, the  fuel filter is a good place to start. If it is very dirty, you may need to remove the fuel tank plug and clean its fine screen also. Next in line is a fine screen filter on the intake fitting of the electric fuel pump, which can also become clogged. Hopefully just the main fuel filter will fix the problem. New gasoline formulations tend to go bad quicker these days, when cars spend a lot of time in storage. You can examine the condition of the fuel tank by removing the fuel sending unit in the trunk and viewing the inside of the tank with a flash light.  Be cautious of flammable gasoline fumes!

[Rolf-Dieter ✝︎]

Hello Louie,

Welcome back, it's always nice to see Members return to our site. Hope your absence was not healt related.

Anyway, not much to add here on your fuel issue other then to say the link from "guyke" above is an exelent one it provides some great deatails of major components on our cars. I can only second that filtration (gas, oil and air) are a major element to smooth operation of our cars. Scroll thru the link from guyke and pages below bring you to some of the items to check.

Page 9, Item 50, Filter Element and Sealing Ring

Page 10, Item 50, Air Filter

Page 11, Item 3, Air Filter Element

Page 46, Items 4 & 5 Fuel and Gasket Sender (Flower Pot as mentioned in the post from Cees above)

Page 46, Item 15 Tank Filter (description for Item 13 is not shown, i think it is the Filter).
 
I'm sure you are aware of this that other item that is important when you store your car over the winter is to sore it with a fuel tank full to prevent moisture to get into the fuel system. Are you driving your car often? A good highway drive at elevated speed (often referred to as a Italian Tuneup) gives good results as well

Let us know how you make out, we always enjoy hearing feedback as to what was found and how it got resolved.

Meanwhile "Happy Motoring"

Dieter