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Marty, ASE Certified Technician
Category: Mercedes
Satisfied Customers: 54835
Experience:  Bosch Certified Master Technician with over 35 years experience in the automotive industry.
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I have '85 280sl(r107). Idles under load perfectly but races

Customer Question

I have '85 280sl(r107). Idles under load perfectly but races when in park.?
Submitted: 2 years ago.
Category: Mercedes
Expert:  Marty replied 2 years ago.
Hi, you will need to check for vacuum leaks at the intake system and check the throttle switch on the throttle body to be sure it is closing at idle. Also clean the throttle body. These are the common causes of high idle. Some of the SL's also had an air bypass screw that you can use to lower the idle speed. I've attached a picture below. Not all of the SL's had the adjustment.