How To Clean A Feuling Electronic Fuel-injection Map Sensor

Fifty-fifty a well-maintained engine will collect deposits of dust, dirt, grime, carbon and oil — both inside and outside. These deposits can cause many problems, such as interrupted air flow, fouled spark plugs or fuel injectors, engine overheating or skewed sensor readings. MAP sensor cleaning may be necessary if you're experiencing poor fuel economic system, crude idle, hesitation or stalling on dispatch, or an illuminated check engine calorie-free.

In fuel-injected engines, the engine control module (ECM) calculates fuel injector pulse based on several other sensor readings, such as engine RPM, engine coolant temperature (ECT), intake air temperature (IAT) and air–fuel ratio (AFR), among others. Air mass is a critical measurement the ECM uses to summate fuel injection, and virtually engines are either equipped with a manifold accented pressure (MAP) or mass air menstruum (MAF) sensor. Some turbocharged engines use both MAF and MAP sensors.

Yous can usually tell if you accept a MAP sensor if y'all cannot notice a MAF sensor in the intake air tube before the throttle body. The MAP sensor is usually mounted directly to the intake manifold, somewhere subsequently the throttle body, though some are mounted on the firewall or elsewhere in the engine bay, connected to the intake manifold via a vacuum line. In some vehicles — older K-cars, for instance — the MAP sensor is mounted by the ECM, connected to the intake manifold via a long vacuum hose. The MAP sensor continuously measures the force per unit area/vacuum in the intake manifold.

Checking a MAP Sensor

Y'all tin can hands test a MAP sensor with a vacuum pump and multimeter. Starting time, remove the vacuum line or remove the MAP sensor from the intake manifold. With the MAP sensor connected and the ignition in the "on" or run position, check the voltage output on the MAP sensor betoken wire. Turbocharged engine MAP sensors volition also answer to pressure level, and their pressure level/voltage readings may be different. Either way, check your repair transmission for the wiring diagram and specific voltage readings.

The typical MAP sensor should read around 4.7 V when open to the air. Using the vacuum pump, you should see voltage driblet to around i V at 20 inHg vacuum. Repeat the test and note that every bit you lot depict and release vacuum/pressure, the voltage should respond instantly.

MAP sensors comprise no moving parts, and they don't typically habiliment out, only cleaning the MAP sensor may be required if it's contaminated past carbon or other deposits from the engine. If voltage is ho-hum to reply to pressure changes, contamination could be responsible.

MAP Sensor Cleaning Step-by-Footstep

MAP sensor cleaning only entails a few more than steps:

Disconnect the MAP sensor connector and put on prophylactic gloves to protect your skin. Safety glasses are a practiced idea, too.
Employ an electric parts cleaner on a soft rag or paper towel to make clean the outside of the MAP sensor.
Spray the electric parts cleaner into the sensor port — a couple of spritzes are unremarkably sufficient. Shake out the backlog and permit the MAP sensor dry.
Cheque the MAP sensor vacuum hose or intake manifold port for additional contamination. Make clean these with electrical parts cleaner and a brush if necessary.
In one case everything is dry, which shouldn't accept very long, the MAP sensor should be articulate of contamination. Reinstall the MAP sensor.

MAP sensor cleaning is an like shooting fish in a barrel fashion to restore engine performance and fuel economy. To go on other air and fuel organization parts make clean, consider an intake organisation cleaner the side by side fourth dimension you maintain your engine.

Check out all the chemical productsavailable on NAPA Online or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more than information on MAP sensor cleaning, chat with a knowledgeable expert at your local NAPA Motorcar PARTS store.

Photograph courtesy of Wikimedia Commons.

Benjamin Jerew View All

Ben has been taking things autonomously since he was 5, and putting them dorsum together again since he was eight. Later dabbling in DIY repairs at home and on the farm, he plant his calling in the CGCC Automobile Repair program. After he held his ASE CMAT for x years, Ben decided he needed a change. Now, he writes on automotive topics beyond the web and around the world, including new automotive engineering, transportation legislation, emissions, fuel economy and motorcar repair.