
Testing A Map Sensor (Again)
#16
Posted 29 May 2018 - 05:37 AM
#17
Posted 29 May 2018 - 07:44 AM
#18
Posted 30 May 2018 - 11:14 AM
Is there an MPI wiring diagram here ?
#20
Posted 30 May 2018 - 04:56 PM
when checking voltage on signal wire you use the 5v supply wire to supply the the ground for the volt meter. if you don't you will get a constant voltage reading. Also confirm from the wiring diagram that you are in fact probing the correct wires for V+ V- and signal
#21
Posted 30 May 2018 - 05:00 PM
But I have T4 kit and its telling me the same thing. My MAP sensor are doing bugger all.
#22
Posted 30 May 2018 - 10:10 PM
Hi,
Usually an ECU would default to using the throttle position to get you home. Wether the rover ECU has this capability or not I've no idea.
The fact that you have a change with it unplugged would suggest the ECU is "seeing" the map sensor. However to have 3 sensors with the same fault seems unlikely, try a variable resistor as you suggested and see if you can change the kpa reading in live data..
Cheers
#23
Posted 01 June 2018 - 12:59 PM
Me again,
looking at the wiring diagram i find this
map wiring.jpg 30.17K
8 downloads
Who can tell me which wire does what, i know the pink is ground.
Is the red one or yellow one the 5v permanent supply ?
Thanks
Pete.
Edited by pete l, 01 June 2018 - 01:10 PM.
#24
Posted 02 June 2018 - 08:53 AM

This is the T4 reading with no Map plugged in.

First map plugged in, engine off, no change. Dead map, brand new

Second map, engine off

Third map, engine off

Fourth map engine off

5 volts direct to the signal wire

1.3 volts direct to signal wire

All views welcome. For me, this is total confirmation that all the map sensors I have are either dead or dodgy. None of them change. Value with the engine running or when a vacuum pump is used on them.
Can anyone be so unlucky ?
I'm pulling my hair out here.
Pete.
#25
Posted 04 June 2018 - 09:29 AM
Anyone have a working MAP available ????
#26
Posted 04 June 2018 - 09:46 AM
the third one looks to be in the right KPA range witht he engine off, and also seems to be a different sensor number.
I'd try that one witht he engine running, or get a suring on it and see if you can get a decent range out of it.
#27
Posted 04 June 2018 - 10:51 AM
Hi, yes the third one is the closest, but still off.
The problem though is that they are all dead. They don't change value with engine running or with a vacuum pump. There must be something inside them that doesn't like getting old and gives up working.
I'm thinking about modifying it and putting a map from k series engines in it, after all, the MGF used the same MAP sensor as th mini when they came out.
#28
Posted 04 June 2018 - 06:36 PM
Hi,
You could try a map sensor off an older Bosch efi system just find the pin specs connect it up and put your vac pump on it and see if you get a change in kpa in the live data. I used a Bosch Saab one I think.
As long as it's got a pipe nipple on it and you can hook it up to the ECU you can prove ECU and wiring is working as it should be...
Cheers
#29
Posted 05 June 2018 - 08:59 AM
I think ECU wise, it's all ok. With 5 volts going to the ecu I get 108kpa, with 1.3 volts I was geting 40 odd kpa.
#30
Posted 10 June 2018 - 09:36 AM



Sucking on the sensor I can get the kpa down to 55.
I'm happy that car wise, everything is working as it should and that I have been really unlucky in buying new and second hand map sensors that are dead on arrival.
Thing is, I don't know what to do now. It doesn't look like the t-map sensor is compatible, seeing as I've only got 86kpa engine off. I might try making up an adapter to fit this and see how it drives.
I have sent the 2 brand new ones back to minispares for testing. Let's hope they can find me one that works.
Thanks all
A happy and very sad pete, who has just lost his mother from heart disease at the tender age of 89 ?????????
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