1997 Mpi Temp Guage Head Scratcher
#16
Posted 15 August 2020 - 01:59 PM
Ran car up today as new gaskets cane for stat still no joy got to top of cold and stayed there no fan on rev up some and it just made it out if cold but when I stopped back into cold it went , aux fan kicked in short time after ,keep head scratching I am of mind gauge or ECU at this point
#17
Posted 15 August 2020 - 07:28 PM
Alice thanks for passing on that contact I'll give him a shout if I'm stuck grateful for your assistance .
So Ado kindly called today with app on his phone that read MPI data and able to reset fault codes great straightforward set up spread the word lol . So data showed ECU was seeing correct temp from CTS but temp gauge to not moving accordingly so thought is faulty temp gauge going to remove dash and hopefully strip gauge to see anything obvious, in the mean time anyone know if these will suit 1997 MPI https://www.preloved...ini-speedo.html
#18
Posted 19 August 2020 - 10:48 PM
#19
Posted 20 August 2020 - 09:01 PM
Cat hot, hot gases leaking into exhaust, open exhaust valve clearance more as a test, spark timing is igniting fuel set by ecu, if the valve timing is out it’s hot gases passing valve/ or if ongoing burned exhaust valves
Having looked at the live data the ECU is seeing the correct temp. Stood there chatting for few minutes observing the data whilst the engine was running. Fan kicked in at the right temp it’s just the gauge won’t go above a the blue line. Seems like a faulty gauge to me
#20
Posted 22 August 2020 - 09:01 AM
Cat hot, hot gases leaking into exhaust, open exhaust valve clearance more as a test, spark timing is igniting fuel set by ecu, if the valve timing is out it’s hot gases passing valve/ or if ongoing burned exhaust valves
Having looked at the live data the ECU is seeing the correct temp. Stood there chatting for few minutes observing the data whilst the engine was running. Fan kicked in at the right temp it’s just the gauge won’t go above a the blue line. Seems like a faulty gauge to me
Or damaged wiring which is introducing an extra resistance and effecting the signal to the gauge.
FS
#21
Posted 22 August 2020 - 09:06 AM
Thanks for that will read through that , I'm pritty sure new CTS is working ok just thinking if I knew resistivity and what voltage / ECU sends to gauge I could link the plug on loom with resistor and test signal going to gauge to see if ECU is giving correct signal out.
Just to add some info to the questions raised in here..
The sensor voltages supplied to the CTS (and others) is 5V (open voltage) generated internally by MEMS. Be very careful doing anything with this to avoid damage.
The output to the gauge is from another part of the ECU and from memory is a pulse generated by switching from an internal 0 point and 5V.
FS
#22
Posted 22 August 2020 - 12:46 PM
sounds like the voltage regulator that supplies 10volts to the temp / fuel gauge.
there's a repair option to solder in a new regulator, [by-passing the original one]
#23
Posted 27 August 2020 - 07:29 PM
#24
Posted 27 September 2020 - 05:27 PM
Not 100% in line with your issue, but I have found (proved) that if you start and MPI and don't blip/touch the throttle, the fan does not kick in until 8'C later than if the throttle has been moved. Bizarre, but definitely happens!
#25
Posted 27 September 2020 - 10:16 PM
Temp gauge reads straight from the ECU.
No resistor.
I have had trouble with the plastic circuit sheet where the gauge earths attach via screws.
I placed a copper washer under each screw head and restored good earths to all gauges.
Simple and easy fix.
Cheers Waz
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