The measuring result by MAP sensor is unstable value and holding at the maximum on sometime. This is the reason why LPG injection system had automatically switch back to the petrol system. Because of the vacuum value of the Intake manifold that was measurement by MAP sensor mismatch or not corresponding with the LPG injection interval timing of engine RPM.
I disassembled the MAP sensor package for checking inside and found vacuum leakage at hose that connecting between fitting and sensor module.
I did repair it by apply some silicone for protecting a leakage problem by coating it onto the fittings surface before connecting the hose then let it cure and reassembly again.
Normally, MAP sensor will be connected to the Intake manifold of engine for measuring vacuum pressure inside the engine that corresponding with accelerator pedal pressing by driver. The installation is use tee fitting to trap vacuum from the petrol MAP sensor hose to get the most matches value between LPG and Petrol systems.
Price of BSM MAP sensor is about 800 Baht for more information please visit http://www.ps-pornsak.com/
