I currently owned a Toyota KDH200. Manfactured year 2006. The Engine is 2KD (2490 cc). (Fuel Type : Diesel)
I had an issue with fuel Consumption so I went to a mechanic. He scanned the vehicle (he plugged an OBD scanner that connected to his laptop), then he told me that one fuel injector was blocked. So he disconnected the fuel line and he ran the engine with a 1 litre of Diesel and some cleaning liquid to clear the blocked injector. With that 1 litre my Toyota KDH van ran for like 1 1/2 hours and then stopped. Then he reconnected the fuel line back to the fuel system, and then accelerate (for full rpm, kind of) and black smoke was coming out. They did this until the black smoke stopped. Then after a couple of minutes there was no smoke and was back to normal. Then he tuned the engine and then we changed the fuel filter, because the earlier one was "black" :D Then that's it on that day. He again connects the OBD scanner, and there were no issues, all was back to normal.
Then this month (October) again I got that earlier issue with fuel consumption. Again it started to reduce. I called that mechanic again and I told that again the problem has returned. So he told that the last option is to unplug the spark plugs and look at those, whether they are working. But he recommend not to do that now. Because it's only 2 months that we have done that engine tune-up and cleared up those blocked injector.
I don't know what to do.. Please help me out..
Thanks !! :)