Hi There.
I have a 1987 300E in excellent condition which I use regularly if I have to collect more than one client for appointments

My other vehicles are a 1998 SLK230 and a 1965 230 SL pagoda

I have had a problem with the 300 e recently.

If it has been standing for a while, it start ok and runs smoothly, then after a while it start idling unevenly when waiting a traffic or stop light and when I accelerate it cuts out and then refuses to start.

If I let it stand for a while it starts perfectly and runs smoothly. Once it runs there are no misfires or erratic running, it seems that the problem dissapears when the car is running at speed

I have replaced the fuel filter, spark plugs and the fuel pump is about a year old. Could it be the fuel accumulator playing up? and if so why does it not happen when the car runs at speed.

Could it be the fuel pump relay

CHRIS

 

I have exactly the same problem. Did you manage to fix it?

 

Hi Namee,
I did sort the problem out
The symptoms were erratic idling especially when the car was in gear (mine has an automatic gearbox) and when the aircon was on

The fault was with the IDLE SPEED CONTROL VALVE
This valve regulates the volume of IDLE air while bypassing the throttle valve
Some volume of idle air is removed by this valve so that more fuel is correspondingly supplied to the engine to ensure a constant idle speed irrespective of whether the power steering or the aircon are used

This valve sits to the right, next to the second cylinder fuel injector. It is a round T shaped valved clamped in a rubber fitting and is controlled by the Ktronic injection control unit

If you remove it you will see that the mechanical valve part sits in the middle of the pipe section. Over time this valve gets all kind of muck in it which makes the valve part sticky

Before I knew the solution to the problem I added fuel injector cleaner to the fuel tank on a number of occasions with good result. The problem would return quite soon however

To solve the problem, remove the valve, then block the one pipe with your finger or a cork and spray carburettor clear in the other side and shake the valve around to get the cleaner into all the nooks and crannies

I did this a few times and then used compressed air to dry the valve out.

You wont believe the amount of rubbish that came out of this valve after 300, 000 kilometers of driving

After cleaning I used a pencil rubber section at the back of the pencil to see if the valve had free movement. As I said it took two or three serious sprays of carb cleaner and some manipulation with the rubber to get the valve moving freely

I have driven the car regularly now for about three months without any problems

Try this as this valve is very expensive from the agents and also replace your fuel filter regularly, Id say every 5000 to 7000 kilometres

Hope this helps

 

Thank you Chris, I will try this as soon as I have time. This car is my second car, so to say - fun car. I did a lot of search on this issue, buy you are the only one who give me a meaningful answer, appreciate it a lot. I'll let you know the results as soon as I get it done.
Cheers.

 

its not a big issue its very easy to solve.