11 replies to this topic

[theoldmini]

Do all mpi minis use camshaft sensor.  Have noticed my mini cam sensor on back of block not connected.  Cannot see any wires close by.  Mine is a 1997 mpi was wondering if they use this sensor.  Car runs v good but will only start from cold with a little throttle. Advice needed if have to can I wire this into ecu and which pins do I use.  Thanks

[Ethel]

I've no real knowledge, but I can imagine it being written in to the code to have a limp mode that runs without the cam signal. Wouldn't explain the lack of a loom connector though.

[mpialan]

Yes, all MPI's use the Camshaft Sensor. There should be a black, two pin connector with a black/blue wire and a red/yellow wire going to the terminals. It has possibly somehow got tucked away against the bulkhead behind the inlet/exhaust manifolds, in the general vicinity.

Happy hunting.

I don't think the MPI has a limp mode as such.

[Quinlan minor]

Wiring diagram

Attached Files

•  MPi Engine Wiring Diagram.jpg   85.69K   8 downloads

Edited by Quinlan minor, 15 May 2026 - 01:34 PM.

[Ethel]

The cam sensor just tells it which 360 degrees out of the 720 crank degrees it's in to know which cylinder to inject towards, the actual injector timing will be taken from the crank sensor. If it didn't know it would still be squirting at the right time (from the crank angle) but not necessarily at the right cylinder.

It could feasibly operate like two 2 cylinder SPI systems.



....thunking about it, with an engine sequence of 2-1-3-4 the outer cylinder follows straight after the inner cylinder on the same port. 1 & 4 would inject as normal, but there'd be 2 extra injector events before 2 & 3 had their inlets open if both injectors squirted in unison. Can't see that working very well.

[theoldmini]

Which pin numbers on ecu would this connect to.  Can someone show on a picture or diagram then I can look to see if this is wired to the ecu.  Car runs fine and passed emission test for mot only the other day.  Have had air cleaner box off but cannot see anything.  More help needed please as thinking of getting electrical help to wire direct to ecu.  Where does the cam wire join the loom.  Sorry to fire so many questions

Edited by theoldmini, 16 May 2026 - 09:15 AM.

[PoolGuy]

Which pin numbers on ecu would this connect to.  Can someone show on a picture or diagram then I can look to see if this is wired to the ecu. 

I think it shows it in the wiring diagram posted above, for me it's too blurry to make out the detail though.

[Quinlan minor]

Red/Yellow C158-1

Blue/Black C158-2

[Steve220]

The engine runs batch injector firing when the cam sensor is unplugged. It wont be as powerful and will run richer.

[theoldmini]

Looking at the last comment I think I will have to look into getting this connected.  I now need the plug that goes into the sensor preferably with wire attached.  Does anyone know where I might get this from or has someone got one in the back of the garage.  Thanks

[theoldmini]

As they say seek and ye shall find.  Well found it hidden behind the expansion bottle.  Sprayed both ends with contact cleaner and connected up.  will take mini out tomorrow but one happy chappy

[Ethel]

Mems is a learning system, don't be surprised if there's no immediate improvement or it even runs worse.