What causes the Volvo S90 to shake and stall after starting?
2 Answers
The reason the Volvo S90 shakes and stalls after starting is due to internal carbon buildup. Carbon deposits typically form on the inner walls of the throttle body, the intake valve heads, the inner walls of the intake manifold, the piston tops, and the inner walls of the combustion chamber. Excessive carbon buildup on the throttle body's inner walls can lead to insufficient air intake, making it difficult to start or causing the engine to stall easily at idle. The Volvo S90 is a mid-to-large-sized 4-door 5-seater sedan equipped with an 8-speed automatic transmission. Its body dimensions are 5090mm in length, 1879mm in width, and 1450mm in height, with a wheelbase of 3061mm. The top speed reaches 230 kilometers per hour.
I've driven quite a few Volvo models, including the S90 series, and the issue of shaking and stalling after startup is quite common. The most frequent cause is ignition system problems, such as excessive carbon buildup on the spark plugs or faulty ignition coils. If the spark plugs are dirty or worn out, the engine will have unstable ignition, causing it to shake a few times upon startup and then stall. Another major issue is the fuel system, such as insufficient fuel supply from the fuel pump or clogged fuel injectors, which can make the air-fuel mixture too rich and lead to shaking. Faulty sensors, like the throttle position sensor, can also be to blame, causing the ECU to make incorrect adjustments. I recommend starting with checking the spark plugs and fuel pump. Don’t skip the hassle—find a reliable repair shop to take a look. Safety first; delaying repairs can damage the engine and increase repair costs.
