I have a 1993 ZX 1.9 diesel which up until now has given great mpg. It has now started drinking the stuff and there are no obvious leaks. Any suggestions/advice would be most appreciated.
I would suggest firstly that you do a brim to brim test to see if the consumption really has dropped and if so by how much. Are you still travelling the same route at the same speed as previously? Is the temperature gauge reading normal and the heater working correctly? Is there any excessive smoke? does it start as it used to? and is there any difference in the performance? Does the engine sound any different?