1995 960 jerking and speed drops
 

Volvo 960 sedan Car 1995 Model (Imported from Sweden to Zambia)
Chassis No YV 1964956S1066672, Eng No 439254(2922cc)

Issues:
1) Car will travel and function normally for 140km and suddenly will choke & start to jerk. Speed drops immediately to 15 to 20 kmh.
2) Car will travel at that speed indefinitely it seems, but no matter how much you depress the accelerator, the car just will not go above that speed.
3) Stop the car for 15 minutes & car will resume normal operation for 5-10 km and then the car begins doing the same thing again.
4) Park the car overnight, then we start again with number 1 above before it starts to happen again.

Volvo Zambia has run the car thru its diagnostics and cannot find a fix.

Please help as I am completely stuck with what to do next.:confused:

What codes did the diagnosis uncover?