Fuel injector knob idle screw position

[barengray]

My 1965 230sl was running with a high idle a bit over  10,000 rpm cold.  I friend of mine took a to take a "look" at it today.  I have never wanted to touch the Idle screw on the back of the fuel injector.  He did without out asking.  But now there is some fuel to the touch around the knob/screw on the back of the fuel injector.  My question is is the knob supposed to be flush to the back of the fuel injector or are you supposed to see the spring?    I don't know how he found it. I can see the spring now.   Also  did he open it up too far and some fuel leaked out?.  The car starts fine and seems to still run high.    I have not taken it on a drive.  The fuel worried me.   Suggestions or should i just get this to my mechanic.  Thanks for any help and i will be sure to never let anyone "look" under my car's hood again.

[ctaylor738]

The idle speed is actually controlled by the air adustment, which is a very large screw/knob with a spring under it on the top right front of the engine.  To lower the idle, you screw it in, which reduces the air.  When the correct idle speed of 750 or so is reached, then the mixture knob on the pump is adjusted to compensate for the additional or reduced air.  This is best done with a CO meter.  Never mess with the mixture knob with the engine running.

To engage the mixture control, the knob has to be pushed in and turned gently until it engages the slot in the adjuster.  It can then be turned and a distinct "click" will be felt.  CW is richer, CCW is leaner viewed from the back of the pump.  If your friend thought that this knob controlled the idle, he may not have known about this engagement.  So if he simply turned the knob, he may not have changed anything.

There is more to solving a high idle than this adjustment.  Read the "linkage tour" sticky here for good information.

[barengray]

Thank you for the information.

[ja17]

Hello,

With a 230SL,  use the little dip stick on your fuel injection pump to check the oil level.  It sounds like your leak may be a result of fuel contamination and too high a level.  Use something to suck the oil out of the pump if it is too high. Removing all the oil and replentishing it with new oil would be best. The fluid level should be at the top mark on the stick after the stick is screwed all the way in.

Yes good advice from Chuck to cure your high idle. Start with the linkage tour.

[ctaylor738]

From experience, when you check the oil level, be sure to have a good-sized pan under the car, because you are likely to have a pint or so of oil come out when you remove the dipstick.