Sorry you are quite correct. Clean ACT and MAP. I have never used contact. I suppose it would be OK. I usually usally use MAF cleaner from autoparts store !
4.9L. On right side of firewall.
5.0L Engine & 5.8L. On right side of firewall.
MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR
Manifold pressure and temperature are used by the ECA to calculate the airflow rate. The MAP sensor responds to manifold vacuum changes due to engine load and speed changes.
The MAP sensor uses frequency to measure manifold vacuum. The MAP sensor is used as a barometric sensor for altitude compensation, updating the ECA during Key On, Engine Off (KOEO) and at Wide Open Throttle (WOT). By monitoring MAP sensor output voltage, the ECA can determine correct rate of spark advance, EGR flow and air/fuel ratio. If MAP sensor fails, the ECA will supply a fixed MAP value and use the Throttle Position Sensor (TPS) to control fuel distribution.
AIR CHARGE TEMPERATURE (ACT) SENSOR
Threaded into a cylinder runner of intake manifold, the ACT sensor provides electronic fuel injection system with mixture temperature information. The ACT sensor is used both as a density corrector for airflow calculation and to proportion cold enrichment fuel flow.
Monday, March 2nd, 2009 AT 11:01 AM