Having problems with your 1992 Lexus Sc 400 ?

I recently bought a 1993 Lexus SC 400 a month ago. The car ran fine. Then it started running rough. At start up it still runs fine. Once it reaches operating temperature the engine idle fluctuates and when put into park or neutral the rpm jumps up. At the same time black exhaust come out and smells like raw fuel. When you step on the gas pedal the engine bogs down and wants to stall. At this point, if you put it in gear the car stalls. After the car sits for a while, it starts up and runs fine u

Posted / edited by AnonymousUser on : 20-11-2017

Answers :

Well as to what you'r describing above, if there is indeed black smoke and raw fuel smell then you vehicle is running rich. That means that insead of having the perfect 14.7 mixture of fuel and air, your engine is burning more fuel then air. The problem is most likely fuel related so if you know enough about cars you can check these areas. First you may want to revise the spark plugs, just to be sure they are sparking enough for a complete combustion. Next the injectors may be clogged up, one of them or a couple. Try removing one of them and taking a look at the spary tip, if very dirty clean it and do the same for the rest. Another possible cause may be sensors as well, Air Mass, Oxygen sensor, Mass Air Flow. Depending on the make of vehicle, sensor location and name may change especially for lexus. The Air Mass Sensor is in charge of calculating how much air is into the engine so that the computer can determine how much fuel to use for combustion. Having that said if the sensor because faulty or dirty with carbon then it can cause the vehicle to burn fuel at different levels for the reason that it may not be accurately reading how much air is entering the engine. My advice would be to take it to a local repair shop for a diagnostic and have them determine what the problem is and if you might be able to fix it yourself to save some time and money.
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Repair Help & Product Troubleshooting for 1992 Lexus Sc 400

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