I just fixed a similar problem with my 97 musso. Replacing the Air Flow meter fixed it. Interestingly just unplugging the air flow meter also fixed the problem, but this would not give optimum performance. For those that don't know, the air flow meter is a short piece of intake tube just after the air filter box. It is a bosch unit and you have to twist the plastic locking ring before you can unplug the cable that attaches to it.
My solution came from here: ssangyong musso mercedes 3.2 motor dies on take ... - JustAnswer
- Main symptom that caused me to look for fix was that the engine started to intermittently loose power and sometimes stall
- When stopping at traffic lights it would Idle very low, or it would surge and hunt wildly and uncontrollably between 500 to 2000 RPM. It was like the ignition cut out and then came on again, or like someone was reving the accelerator
- Sometimes it would idle ok and then it was like the ignition suddenly cut out and then came back on. Sometimes it would stall, but if it didn't then it would hunt as per above.
- When the engine was cold it was OK - I think because it automatically runs rich when cold - like choke. But after 5 mins or less of driving, issue would occur.
- Idle was not rough, except when it cut out
- when issue happened at lights, sometimes idle would go very low despite foot on accelerator and would have to push to wide open throttle. After 10 seconds or so it would go.
- A symptom that may be a precursor to full blown failure like the above is that it would stutter on takeoff. IE when you are stopped and go for the accelerator, it would die a bit then take off.
I hope this helps someone solve their issue.