Problems with Toyota Crown 2020: Unsteady engine, black smoke and increased fuel consumption

Hey, I had a similar problem with my Toyota Camry, year 2018, so a similar model but a bit older. To understand, I am not a car mechanic, but I have had some experience with car repairs. I went to a local garage and after some research they found out that it was incorrect software values for the fuel pump. The guys at the garage reprogrammed the software and it cost 45.0 euros. It's always good to have all the information about your vehicle. Could you give me a few details such as the engine type or the exact mileage? Maybe I can then give you a few more tips.

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Hi, thanks for your reply. My Crown has a mileage of 54791 KM and its last service was recently. It is a gasoline engine. Hope this helps to get some more suggestions. Quite expensive that they took 45.0 euros for a software update. Hopefully I can avoid that with my Crown.

(Translated from German)

Hey, thanks for your quick reply. It's always annoying and you want to get it off your plate as quickly as possible. With the mileage, I really wouldn't put the low pressure fuel system as the main problem, unless there was grossly negligent behavior involved. With the description of the symptoms, the following things could play a role: First of all, rough engine running is a classic indication of ignition problems. Perhaps the spark plugs are worn or the ignition distributor is defective. Check this, spark plugs are quite inexpensive and easy to replace. The strong exhaust smell and the black smoke could indicate a problem with the air-fuel mixture in the engine. This usually means that too much fuel and not enough air is burning in the engine. Check that the air filter is clean. If it is clogged, the engine is not getting enough air. The other symptoms - loss of power, stuttering at idle and increased fuel consumption - could be a sign of a problem with the fuel system, perhaps the pump is faulty or the injectors are clogged. Maybe do these checks first and then get back to us. You may already be able to rule something out or determine something. Hopefully this will help and you will get closer to the problem. Good luck!

(Translated from German)

Hey, thanks for the detailed advice and the time you spent on this. You're right, it could be that there are multiple problems. I'll check the ignition problems and the air filter first as they sound like inexpensive repairs. I'm not a professional, but with your instructions I should be able to do it. If I have any questions after the check, I'll get back to you. Hopefully it won't be too expensive. Keep your fingers crossed for me!

(Translated from German)