Over fuelling Issue, W116 350SE 1974

I have often come across this on Older Mercedes with Djet. I have found that one of two injectors are faulty and the car runs poorly, so someone gets the bright idea to up the pressure . I am tuning a 3.5 300SEL right now which had 34PSi . Adjusting it back to 28PSi has stopped it running rich but one leaky injector (#6) causes the pressure to drop off drastically under acceleration and foul number six plug. I don't use a tester machine for testing the various components ,Just a snap on multimeter . It only takes 30 minutes to go over everything. As a side note, you can buy a pressure gauge at any auto parts place in ZA, you don't need anything too fancy (or expensive) Mine is just an old Oil pressure gauge.

Hi guys,

we are a small family here and appreciate to be signing and greeting by first name. Would be great if you could accomodate with that.

Good Morning Folks.
I am returning to this website and group after a long two year covid induced lay off. I am not sure if Volker is still around and therefore addressing myself to everyone.
I have a strange 1980 W116 350 SE V8 problem. when car is cold it does not accelerate well, cuts out and then struggles to start. When it does drive it does not pull and splutters all the time. Once its fully warm it then drives ok with and occasionally will not respond to the accelerator. This points to warm up regulator. I did the following over a period of time before getting to WURb.
1. New coil and new plugs.
2. Checked and changed rotor.
3. Changed fuel filter and fuel pump.
4. Warm up regulator cleaned reset.
5. Replaced Warm up regulator with used one cleaned and reset.
6. Removed tank cut open cleaned and welded back together.
7. Fuel accumulator is relatively replaced with new part a few years ago.
After all this problem still persists and only goes away after putting in fuel line cleaner fluid. The car functions fine for a few days and weeks maybe.
8. This weekend found two used WUR with no change when cold and again after putting in a bottle of fuel line cleaner car functioned well, accelerated etc.
Help....dont know where to go from here.

I forgot to sign off my previous message.

William Davy
South Africa

Hi William,

if I was not around any more, this website would also not exist. So yes I am still here and I do run 7 workshops on D-Jetronic and K-.Jetronic this year.

You talk of WUR but you claim a 1974 350 SE. That should have D-Jetronic and no Warm Up Regulator but a MAP sensor.

Hi Good to hear that you are still around.
This is a different 350se sir. I have two 350se 1974 and 1980. this problem with WUR is the 1980 one.