Warm up issues 450SL 78

My name is Kevin and I live in Michigan. I purchased a 78 450 sl a few months back and have been enjoying myself working on it. I am finding that it is a well built car and it is my first MB. I really enjoyed rebuilding the brakes, front end, cooling system and fuel system. The car runs great, except when it warms up, it starts to stumble a little upon first acceleration. Since I have replaced the entire fuel system in the back and cleaned out the fuel tank, I am considering purchasing a rebuilt wUR.

Any advice would be greatly appreciated

Hello Kevin, welcome at Oldtimer tips.
Somebody will help you to get your 450sl running smooth.
Rudiger
Hollywood , MD.

Hi Kevin,

you need to measure system and control pressure between your fuel distributor and warm up regulator. Your control pressure determins how rich or lean your mixture will be. I have recently written an article how to build a K-Jetronic fuel gauge. Unfortunately it is in German and I still have to translate it.

Article building a K-Jetronic fuel gauge in German

I was able to translate this article to english. But, It is a little overwelming procedure and not sure I have the capability to do this.

Hi Kevin,

have a look at configuration MB-KA in paragraph 6. It tells you which parts to buy. After that you can measure your system and control pressure and find out whether they fit or whether you need another WUR.