Why does my 72 350SL idle up and down?

Why does my 72 350SL idle up and down?

The reason for the up/down idle is that the closed throttle decel cut-off is initiated at around 1800rpms. That means that at 1800 rpms with the throttle closed the fuel is cut untill the idle speed drops to 1200 or so, where fuel delivery resumes. If you wish to see how high it would have idled, pull the throttle switch wire.

When does the engine stall in a Mercedes?

There are never any notifications on the dash or any signs of it beginning to fail. This typically happens when I’m slowing down at an intersection or just driving slower in traffic.

Is the C220 CDI eratic shaking at idle?

C220 CDI Eratic Shaking at Idle. Discussion in ‘ Engine ‘ started by Pillabenz, Nov 18, 2012 . Evening folks, Just bought another Mercedes. This time its a C220cdi Auto. 01 model. Car dives excellent, very responsive, very pleased with it.

Why is the idle speed not going down?

Vacuum leak is a likely culprit if you can’t get the idle speed down enough even with the idle air screw fully shut (and the AAV is closed, of course). I would venture that smooth running in gear implies reasonable injector/manifold seals (leaks here affect one cylinder at a time causing rough idle).

How does the gas pedal work on a Mercedes?

Since 2000 Mercedes has been using drive by wire system. Which means you press the gas pedal but there is no cable connected directly to the throttle valve. Instead, there is a potentiometer that detects the position of the gas pedal.

What causes the throttle body on a Mercedes to fail?

When there are throttle body malfunctions the wrong amount of air enters into the engine causing problems with air/fuel mixture ratio. Here is a close up picture of a Mercedes throttle body. Mercedes throttle bodies made by Bosch and VDO may fail. Luckily these units are repairable.

Are there any problems with the Mercedes transmission?

Including Engine, Transmission, ABS, Airbag, SRS, SBC Brakes, ESP, EPS, Air Suspension and more. In depth troubleshooting, but only works on MB cars. 2. Launch Creader X431 VII works in European, Asian and Domestic Cars.

There are never any notifications on the dash or any signs of it beginning to fail. This typically happens when I’m slowing down at an intersection or just driving slower in traffic.

What causes idle speed variation on 1972 280 SE?

A drop or two of oil on the felt pad under the rotor every 5000 miles or less). If it sticks, it can snap back and forth rather than moving smoothly, causing idle speed variation. A leaking vac retard on the distributor can make trouble, too. 1972 280 SE 4.5 165, 000 – It runs!