Is it my Vacuum system ?
 

1982 W123 - a 200 euro saloon model
I have been having issues with acceleration to full power ( 109hp gasser)
literally had to downshift to 3rd gear to hit in the 30mph range. 4th is maybe topping out at 50mph on flat highway roads only.
I am thinking or hoping this can be a vacuum leak issue somewhere.
Other issues that popped up recently are my brake pedal out of nowhere got soft and my trunk lock stopped working. edit * my door locks sometimes open and other times not.
I'm in a small town in Northern Colombia and they do not know these cars here very well.
Recently installed new plugs, ignition wire set, distributor cap and had my tank filter cleaned. I was told it had some rust clogging it. Hoped that was my solution but here on day 2 i just had all of these issues pop up.
Please offer suggestions ..Is the vac system related to brakes and acceleration in any way? Thanks!

30 views. No ideas? Is the vacuum system related to these issues?

It may help to treat this matter as two issues.

1) Engine performance.
The first thing to check is ignition timing. Do you have access to a timing light, and if so are you familiar with the use of one?
Second, in addition to the tank screen, there should be an inline fuel filter between the pump and the carburetor. If there was rust in the tank screen (common), the inline filter may be clogged.

2) Vacuum
An engine that is operating with retarded ignition timing will have very poor manifold vacuum, and hence the supply to the chassis will also be poor.
The chassis vacuum system, being composed of a number of plastic pipes connected by short sections of rubber tubing, offers many points for leaks. All of those pieces of forty year old rubber tubing are prime suspects for leaks.

Thanks Frank. I'll have to ask around if anyone within the 2 hour drive to a larger city has an engine timing light. So I'm hoping I found the culprit of the poor engine performance. Somehow my #1 ignition wire was not put on tight or came loose. I snapped it back in and have driven short distances so far without a noticable issue.
It is good to hear that this might have an effect on the vac system. 🖐️👍

Did your vacuum hose pop off your distributor? Sure sounds like a vacuum hose somewhere fell off.