Any KJetronic experts? Mercedes 300CE cold start problem

[swampy442]

As per the attached Youtube vid, starts up fine holds a nice cold idle for a short while then suddenly drops right down, if you hold it on the throttle it at a certain point it starts to hunt. If you turn it off and restart it you get the same result. Once warmed up it idles nicely, smooth and about 700rpm.

Ignore the rattling noise, its just the aux belt tensioner.

Any valves to check, sensors to look at etc?


https://www.youtube.com/watch?v=PM7TpqXc3pc

[Rayy]

Leeford Motor Co in Leeds sorted KE Jetronic issues on my w124 230E quite successfully. Depends if you're anywhere near Yorkshire, I guess.

I've no connection to this garage - other than as a customer.

[swampy442]

Still looking for help on this, if there's an expert in our midst

[njw1]

I'm definitely no K jet expert and it's been many years since I worked on a K jet sytem (and it was in an XR4i not a Mercedes!) but from memory cold start problems were related to the cold start valve, thermotime switch, cold start relay or auxiliary air valve. I found a useful guide on how the system works here;

https://www.volvoclub.org.uk/tech/fuel_injection/B...