What are the symptoms of a faulty intake pressure sensor?
2 Answers
Intake pressure sensor failure symptoms: the car won't start, and even if it does start, the driving speed becomes unstable with poor acceleration. The ECU's operation relies on three key components: the coolant temperature sensor, intake pressure sensor, and crankshaft position sensor. If the intake sensor fails, the ECU loses accurate intake air volume data, leading to operational faults. The intake pressure sensor, abbreviated as MAP, connects to the intake manifold via a vacuum tube. It detects vacuum changes in the intake manifold corresponding to different engine speeds and loads, then converts these changes into voltage signals through internal resistance variations. These signals allow the ECU to adjust fuel injection volume and ignition timing.
I've been driving my old car for a few years, and recently encountered a faulty intake pressure sensor with quite obvious symptoms. Starting the car was particularly difficult, often requiring several attempts before it would barely start. At idle, the engine shook violently, causing the entire body to vibrate. On the road, acceleration was weak, feeling like there was no response when stepping on the gas, and climbing hills was a struggle. Fuel consumption also suddenly skyrocketed, burning several extra liters of fuel within a week. The small yellow engine light on the dashboard stayed on, and I knew something was wrong. Later, when I took it to the repair shop for inspection, the mechanic told me the ECU couldn't read the correct pressure data, causing the air-fuel mixture to be off, and the spark plugs had also accumulated carbon deposits. Fortunately, I replaced the new sensor in time, otherwise the car might have stalled on the highway—safety first, after all. It's important to pay attention to the car's condition regularly, as routine maintenance can prevent many issues.
