Discussion and questions related to the course EFI Wiring Fundamentals
Hi i am having a small issue with my setup, its a gc8 impreza with a wire in G3/4 link, i am running a honeywell 150psi oil pressure sensor.
on pclink i have configured the anvolt4 to 150psi ti sensor. issue is that without the engine running (has also been sitting for a week) it reads 143kpa or 14.3 psi.
What would cause this? could it be a wiring fault or is at a calibration issue or faulty sensor? it is using 5v out from ecu shared with tps, and sensor earth. voltage reading is 0.88v aswell.
appreciate your help
Is it reading 143 kPa, or 14.3 PSI (98.6 kPa)? they are two separate pressure values. If it is reading the 14.3 psi value, then it is most likely that you have used an Absolute calibration for the sensor, and the sensor is reading the ambient atmospheric pressure where you are.
they are the values that are coming up on pclink... i did a custom cal table today for it and its the same, data i used was
0.5v = 0psi, 4.5v =150psi
any idea what is going on?
The data you used for calibration are good, and the fact that you have 0.88V correlate the fact that you see 14.3psi.
Have you tried to remove the sensor from the engine and check the voltage to see if you read 0psi ?
If you have 0.88 volts then the ECU is reporting the correct pressure - It should be seeing 0.5 volts with no oil pressure.
I would be confirming your zero volt and 5 volt connections at the sensor as well as the integrity of the signal wire back to the ECU. If this all checks out then you either have a faulty sensor or an engine that magically has oil pressure when it's not running :)
If the sensor is a Honeywell MLH series sensor, then the bottom value that it reads should be 0 at ambient pressure, as the MLH series read only Gauge pressures, not Absolute. Therefore the sensor, with the engine switched off and no oil pressure should be reading around 0.5v and 0 pressure.
Are you able to post up the complete part number from the sensor.
Sorted this issue! the supplier of my sensor found my post on the link forum and called me to let me know they had accidentally been supplied a batch of absolute pressure sensors mine being one of them. so made a new call table .88v = 0psi 4.5v = 150psi and it all works perfect now! now just need to sort the intermittent no start issue thats plaguing me...
full scale is 150psi absolute - not gauge. Therefore you should set full scale to 150psi less atmospheric pressure (approx 135.5psi).