A MAP sensor will be required in all cases except for naturally aspirated engines with very aggressive camshaft profiles. The MAP fluctuations caused by large amounts of overlap result in a very unstable MAP reading especially at idle. Also note that multi-butterfly engines often give a poor vacuum signal. In these cases, it is best to use the throttle position (rather than MAP) to indicate the engine load. In all cases where forced induction is used, a MAP sensor is required.
G4X Monsoon ECUs have an internal MAP sensor. If a higher pressure is required than that of the internal MAP sensor, an external MAP sensor can be wired to an Analog Volt input. To use the internal MAP sensor connect the MAP pressure hose to the barbed hose fitting on the ECU.
G4X Xtreme, Fury, Storm and Atom ECUs require the wiring and mounting of an external MAP sensor (if a MAP sensor is to be used).
The MAP sensor must be connected to the inlet manifold via a suitable length of 3mm (minimum size) vacuum hose. The take off point must be between the engine and throttle plate so that the MAP sensor registers vacuum (as well as pressure on turbo applications). The take off point must be from a common chamber that is connected to all cylinders rather than off a single intake runner. The fuel pressure regulator's pressure signal is usually a good take-off point. However, do not be tempted to share the MAP sensor vacuum hose with other devices such as a boost gauge or in particular a blow off valve.
Suitable manifold take off points for MAP sensor hose
Ideally the MAP sensor should be mounted higher than the inlet manifold so that moisture will not condense in the MAP sensor.
Wiring of a MAP sensor requires the connection of three wires:
1.Signal - The MAP signal must be wired to an Analog Volt input. Configure this input as MAP sensor and select the appropriate calibration in PCLink.
2.Power - The ECUs +5V Out can power +5V MAP sensors otherwise power the sensor as per manufacturers specifications.
3.Ground - The MAP sensor MUST be grounded back at the ECU using a green Sensor Ground wire, not the engine block.
MAP Sensor Wiring