230SL, 1965

[Grey Ghost]

New member having running issues with 1965, 230SL, European model. I am retired military and brought it back from Germany over 35 years ago. Over the years I have had to store it for long periods as I moved around. I am not a mechanic or as skilled as I should be after all these years. However, I have always been able to work out issues, keep it on the road, and enjoy. Recently I could drive about 30 minutes/20 miles and it would shut down. The motor would turn over as if no spark or gas. After 10-15 minutes it would start and run as if nothing was wrong. This would happen almost at the same point over and over. When it running every thing checked out OK. I changed fuel filter, new plugs, tried a different coil with the same results. Next I followed some forum WRD postings, took it apart/test/lub/resealed. Really took two steps backwards. Now it runs rough, won't idle, no power and I can barely get it out of the drive way. Also found that I get almost no response now when I  attempt to adjust the engine idle.
What could I have messed up or am I looking at a major problem with the injector plumb?

[Rodolfo]

maybe some rust in fuel tank?

Rudy

[garymand]

Please tell us what you changed, hopefully it wasn't too many things.  To fix the idle you will have to undu something you did.  Rust in tank is a possibility: you didn't mention the fuel filter.  It is in aaluminum canister attached to the motor mount arm on the WRD sidfe of the motor.  The fuel pump is like a garbage disposal: it has little blades that chop-up any rust coming through with gas.  The rust becomes very fine particulate that will not go through the filter, (nice work on the engineering side).  The particulate builds up on the filter and finally plugs it.  It ia a very big gas filter.   Pull the filter andf pour the gas into a clear container.  You lots of orange powder / sediment in the gas.  It settles out as sediment and falls off the filter as the car sets not running.  Start the car again and it takes a while for it to get curned up and cover the filter again.  Mine was so bad I could go through a stop light once it was stirred up.  The tank sounded like it had a pound of sand slushing around on the bottom.  It doesn't happen often, you need water on the bottm of the tank and I don't know how that much water can get in. 

The running problems will need to wait until the tank is fixed.  BTW, no damage from the rust to the engine thanks to the filter.

[KevinC]

Unfortunately, it may be a handful of things. I just discovered a stuck check valve on the output side on the fuel pump. Its probably smart to start with the fuel filter and work your way back.

[Grey Ghost]

Thanks for the information. I replaced the current fuel filter less than a year/100 miles ago. But that sounds like the place to start; will do and keep all informed.

[alaska230sl]

Have you replaced the ignition coil?  Old coils get hot, wires seperate, the vehicle won't run.....cools down, wires get back together (sort of) and of I go...had the same problem on a '71 GTO, a '76 Harley and a '66 Chrysler 300.  That's all it was.  Coils are cheap, but make sure you get the proper one for your car, ie: do you have an external ballast?  Good luck! Steve.

[Grey Ghost]

230SL mechanical fuel injection pump issues. I have tried a number of suggested things to correct running problems: new fuel filter, different coil, adjustments to the idle screw on the back of the pump. But got to the point where it would not start. I had a car shop look at it; they said there was not enough pressure out of the mechanical pump through the lines to the injection valves. Suggested I find a dealer or someone with a working knowledge. Any suggestions on how or where to get the pump serviced/rebuilt?

[Benz Dr.]

Rebuilt pumps are available on an exchange basis. Fuel pressure and volume is what you should be loooking for. The fuel filter is often cited as a place to look but I honestly can`t see how a filter that big would ever get plugged. Maybe a place to look but not the first place to look.

[ctaylor738]

Sent you a PM about resources in the DC area.

[Bob G ✝︎]

Check the coil that the same problem I had . I betting that is it.
Bob geco