Generic Sensor input error

[Bmettie]

I noticed my oil pressure to low when driving a few weeks ago. After swapping in a new sensor and digging through logs it seems to me that the signal is having an issue, maybe with temp. Oil pressure reads zero when cold but after the engine is hot the reading is negative, I've seen values from -6 to -8 after a hot engine shutdown. Overall oil pressure when running hot is also lower than normal. I've verified with a mechanical gauge that it is reading off when hot. I was thinking about swapping the input at the MS3pro to see if it changes. Can an input drift like this with temp? Any ideas on things i should check?

I have a long log after swapping with a new sensor from engine off cold to engine off hot, as well as logs from a week prior to the issue where the signal was reading fine when the engine was hot. It looks like something happened between 6-3 and 6-10. I put in the new sensor on 6-11.

[Bmettie]

The long log is too big so it is here
https://drive.google.com/open?id=0B0hS2 ... WNZbVBlVUU

[billr]

I gotta ask... is this a reliable sensor from a vendor like Digi-Key, or a cheapie from ebay? Have you checked voltages right at the sensor with a meter (all of them, signal, power, and ground); referencing the meter to MS ground?

[Bmettie]

I gotta ask... is this a reliable sensor from a vendor like Digi-Key, or a cheapie from ebay? Have you checked voltages right at the sensor with a meter (all of them, signal, power, and ground); referencing the meter to MS ground?

TBH I don't recall where I bought the sensors from. I bought 2 when i purchased and installed the MS3 a couple years ago. One is for fuel pressure and the other for oil. I haven't had an issues with the fuel pressure. I had an digital oil pressure gauge that used a 10 bar sensor so I used that sensor until, this issue on 6-11, when I installed the "new" sensor. The issue occurs with both sensors. The old sensor was used for ~2 years with the MS as well as a few years before MS. I checked the voltages at the connector with the sensor disconnected only to check the wiring, i haven't checked with the sensor connected yet. Is there a way to make TS output the raw 0v-5v value the MS is seeing so I can compare what I read at the sensor? I'm going to get out to the garage today. I also have a fuel pressure sensor, BARO sensor, MAP sensor and TPS all being feed from the same MS3 5v. Those all appear to be fine.

[billr]

To get voltages to compare to a meter, set the sensor linear "0V" value to 0, and set the "5V" value to 5

[Bmettie]

To get voltages to compare to a meter, set the sensor linear "0V" value to 0, and set the "5V" value to 5

Yea I realized that after the coffee kicked in yesterday. Never got out to the garage yesterday, hopefully going to make it out there today.