Lou -- so if yours is like mine it's jammed in the full rich position. I can feel the knob but can't see it... it's hidden under two solenoids (or somethings) above it on the back of the pump. I can't push the thing in, find the slot it needs to go in, and get a wrench on it all at once. I'm thinking about putting the car on jack stands and trying to access from below.

Let me know if you have any success.

So give it a go, gently, with a small pair of vice grips. You want to turn it CCW viewed from the back.

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

Off for a final trip to the lake today! I'll give it a shot tomorrow night.

He gang, those pumps were 6 plunger pumps, some had one solenoid and some had 2. The solenoids had 2 functions, one was for start enrichment meaning when the starter was cranked the solenoid moved the main rack causing it to deliver more fuel to start the engine. The other was for fuel shut off during deceleration, it stopped the backfire or popping noise in the exhaust during decel. The knob at the back of the pump is for idle fuel delivery only, it has no effect on fuel delivery at speed. There are other adjustments for other ranged of engine operation. I have never had to use a tool to adjust the idle rack, shouldn't need that type of force and never ever gets set with engine running. The other adjustments are internal in the pump and require a chassis dyno to perform. As for idle air you need to check for thermostat function at the injection pump for cold running enrichment, it's very important.
Bill

OK I finally got mine going. The adjuster knob on mine was not round, but more like a miniature water faucet handle. I put a 6-point 15 mm socket on it (put a few small washers inside the socket to help push) and got it moving.

Thanks to the excellent instructions here...
1970 280SE 108 018 6 Cylinder Runs Rich

... I got it running really good and feel like a genius. It was so screwed up... the throttle was cracked open at idle and the air bleed screw was opened up so far it wobbled.

I know it sounds crazy but I think it runs better now and shifts more smoothly (less jerky). At this point I can see the constant speed solenoid is not functioning but I'm pretty happy.

which way did you turn yours counter clockwise or clockwise?

Counter clockwise. I think doing it with a cold engine helped too.

did it Sunday, 2 clicks CC. No more black smoke out the exhaust, and my eyes don't water behind the car while it's running! I've been able to run it at idle for over an hour total without fouling the plugs. Driven it about 3 miles and still runs strong. Keeping my fingers crossed! THANKS TO ARTHUR DALTON AND YOU.