Whilst moving my air intake over to the cooler side of the engine away from the exhaust a thought occurred to me… I’m going to all this trouble for maybe a degree or two but actually how accurate is the inlet air senor anyway?
Using a scan tool and a thermocouple attached to a calibrated thermometer I did a quick check on my IAT sensor’s output. Surprise surpirse my sensor was reading around 15% high. Not ideal. The ECU will be being fooled into thinking the air is a bit hotter than it actually is. Don’t really know how much difference it will make but I guess my engine might be running a tad lean when in open loop mode so thought it best replace the sensor.
My duratec uses a TMAP sensor which is a combined IAT and MAP sensor all in one. I ordered up a new one and tested it as soon as it arrived. It was exactly the same as the original around 15% high. Returned that unit and ordered another and that was even worse at around 20% high.
I apologise in advance to all the wincing electrical experts reading this (I am not). I decided to break into the new sensor and attempt a little surgery. I cut a square hole in the front face, cut the track on the pcb running to the thermistor and wired a 10k pot in series.
Butchered sensor re-assembled and filled with epoxy to re-seal. Did a quick test to check the MAP sensor was still working ok after the trauma and all was well. I now have an adjustable IAT sensor that I can set to the correct temp….. well actually I have biased it a little on the cool side
And by the way, here’s a pic of my new repositioned cool(ish) intake. I wonder if it will all actually make any difference
