Need Help Getting 250sl Just Out of Storage Started

[duffelpud]

I purchased a '68 250sl in April and have been cleaning out the fuel system.  This evening I re-installed the gas tank, installed a new fuel filter, hooked up the fuel lines, installed the battery, poured 3.5 gallons of fuel in the tank and attempted to start it up.  Nothing.  It turned over, but didn't catch or even sputter.  The fuel pump is making a delightful whirring noise, so I assume it is sending the petrol along its merry way.

Is there any trick for 'priming' the system?  Any thoughts before I turn it over to my mechanic?

[Raymond]

Welcome Duffelpud,   

There are several threads to on the site for awakening long slumbering SLs.  There are a ton of things to check.  How long has it been since this car ran?  We presume you did more to the car than just clean the fuel system, though that was a great and prudent begining.  Did you check for spark?  Did you check the points for condition, operation, and gap?  Have you checked the valve clearances?  Does the Cold Start Valve work?  Is there fuel leaving the FI pump?

That should get you started, if not the car.  If all that is good, then we'll help you chase other leads.  Good luck.

[duffelpud]

Just checked the injection pump via the removable cap at its front and it is not frozen, however the return line at the gas tank is not producing any fuel when disconnected with the pump running. 

[ja17]

What is not frozen? Did you check the rack or are you referring to the the cover itself?

[duffelpud]

The rack itself was not frozen.  Since then I determined the pump was not delivering fuel, although it was making noise like it was turning.  I took it out, removed the bottom cover (using the excellent rebuild guide found on this site as a reference) and found that the small woodruff key had slipped out of the notch in the impeller, keeping the motor from turning it.  It was slightly worn on one side, so I tried re-inserting it both ways and found that it worked better one way than the other.  I reassembled it and - presto - fuel moved through the lines and before long the engine started.  That's when I noticed gas dripping from the overflow spout on the back of the pump. Next I'll have to remove the pump again and inspect/repair the bellows seal and O-ring.

[glenn]

'68 250SL??  Could be, but most likely a '67.  Could be one of the last built in '68?

[Naj ✝︎]

  That's when I noticed gas dripping from the overflow spout on the back of the pump. Next I'll have to remove the pump again and inspect/repair the bellows seal and O-ring.

Probably the little one on tha armature. I found one that had shrunk and gone hard.

Naj