Q: Fast idle - 1983 Mercedes Benz 380SL

asked by on September 08, 2016

My car has a very fast idle when you first start it up. It will idle high. But when you tap on the accelerator the idle will slow down for only a minute. Then it'll go back to the fast idle. Do you know how I can fix this?

Throttle Position Sensor Replacement $129.21 - $646.10 Get a Quote
Clean Throttle Body $93.59 - $291.31 Get a Quote
Engine idle speed is high Inspection $79.99 - $89.99 Get a Quote

Hello. There could be a problem with the throttle cable sticking, causing the high idle. There also could be a problem with the throttle position sensor malfunctioning, causing a high idle. Sometimes a dirty throttle body can cause this problem as well. All of these components should be inspected by a certified technician, like one from YourMechanic, who will be able to diagnose the high idle and make a recommendation for repair.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

What others are asking

After 10 minutes driving, engine stalls - 2003 Saturn LW300

Hello. It sounds like you are having two different problems. The first is the stalling. I think your fuel pump is causing the stalling. The second is the wrench light and transmission not shifting correct. I think it may be...

Car won't start. Can't determine if either ISM is bad or hydraulic valve body need to be replaced.

I presume your saying that your car does not crank when you turn the key, because that is the only fault I would expect to be associated with transmission parts controllers.The ISM (intellegent servo module) is responsible for the transmission...

Smoke from the dashboard, parking lights won't turn off

Hello. It sounds like there is a short in the wiring harness of the car. If the wiring comes into contact with other wiring, this may cause a short and smoke from the dashboard. This sometimes happens due to old...

Hesitation on take off

A hesitation present during acceleration is usually a sign of a fuel delivery or fuel ratio problem. Naturally, this will be enhanced when the AC is on since the AC increases the load on the vehicle's engine more than normal....

Clicking sound coming from engine, increases with acceleration.

It sounds like it could possibly be a motor mount or transmission mount causing the problem. If you see a lot of movement in the engine when you have it in gear you probably have a cracked or broken motor...

Car sputtering upon acceleration.

There are a lot of issues that could cause the symptoms you are having, from a faulty mass air flow sensor to a clogged catalytic converter. I suggest you have your vehicle inspected by a trained mechanic, such as one...

When I accelerate it has no power. It only goes slowly. I have a code PO700 that has came up.

Hello. Code P0700 is the trouble code for an issue with the vehicle's transmission control system. If the computer detects an issue within the transmission control system it will set off the Check Engine Light in order to alert the...

Car is vibrating when accelerating - 2003 Chevrolet Trailblazer

Hi there. There are several possibilities for the vibration and lack of power upon vehicle acceleration. The missing fuel cap should not affect drivability. Assuming the Check Engine Light has been on for the missing fuel cap, this leads me...

Engine not turning over

There are many reasons why a car won't start. Everything from a low battery, fuel pressure issues, to ignition system problems, crank and cam sensors, engine timing, etc. Because of all the variables and the limited information, it is very...

Related articles

How a Modern Engine Works
You You turn your key in the ignition, and the engine fires up. You press the gas and the car moves forward. You take the key out and the engine turns off. That’s how your engine works, right? It's a...
Symptoms of a Bad or Failing Crankcase Vent Filter
Common signs include oil leaks, excessively high idle, and a decrease in engine performance, power, and acceleration.
The Importance of Warming Your Car Before Driving
Scandphoto / Shutterstock.com Many people feel that it’s important to warm a vehicle up before driving off. This has long been the dominant school of thought, dating from when cars had carburetors and many would not run...