Modified ignition knock sensor detonation sensor. This device controls ignition timing of volvo 240 series from 1983 through 1988 . Do you have one on your car ? If there is a large ignition control module next to the windshield washer container on the passengers side of the car you do have one.
The knock sensor is responsible for all of your excessive fuel consumption, black smoke out of the exhaust pipe, rough starting , car stalling at the intersections and in stop and go traffic.
If you experience any of the above conditions - it is time to replace knock sensor. No guess work.
The knock sensor is located on the engine block , between cylinders 2 and 3 next to the temperature gauge sensor. Both sensors have flat blade electrical connector terminal . The temperature sensor is visibly smaller in size . Please pay attention when removing electrical connectors.
When installing a replacement sensor - please remember that it only requires to have 8 ft/lbs or 11n/m of torque. That is basically hand snug with a wrench. Please remember to add anti-size compound to the thread of the sensor prior to the installation.