Hi!

I got a 1981 Volvo 244 (manual) from a friend four years ago and since about last year the fuel efficiency went down about 25% (400 km / 55 liters before, 300 km now). Spark plugs are less than 1 year old. The car still drives nicely, the engine drags well, just more expensively :) My wife drives much gentler than I do, but that doesn't seem to make any difference.

The engine was always a bit irregular on idle, and lately it sometimes stops when pressing the clutch after a longer highway driving (i.e. when going from high rpm to idle).

Any ideas?

Thanks!

I would start with new plug wires/cap/rotor/air filter, etc. if possible - a general tune up.

Its probably running too rich - look at one of the plugs to see if its black or wet with gas. Possible causes could be a bad o2 sensor or coolant temp sensor, or the related wiring.