3 replies to this topic

[JasperNL]

Hello everyone, 

This is my first post here, but quite a challenging one in my eyes. 

During the past year I rebuild my own 1994 Mini SPI. 
At the moment I have completed a engine rebuild and some other bits and bops. But running into an issue with starting.

When cranking the engine via the ignition, the startermotor engages and disengages multiple times per second. Which of course is not ok.

I checked my wiring and realys clompletely using the Haynes manual and a multimeter. All of those should be correct. 

I had the startermotor checked by a specialist, which is also ok. I confirmed this when "shorting" the starter on the plus, it engaged perfectly fine then. 

Below I have listed a video for a visual explanation of what is happening. 

 

I have discussed it with multiple people at work/school/everywere , but nothing really came from that. Thats the reason for asking here. 

The only thing that I can come up with is having a bad earth to the battery, but I am not really an electronics expert.

 

I hope that you can help me, and thanks in advance!

 

https://youtube.com/shorts/HemTKrsRkf4

[Ethel]

It would be a classic symptom of a flat battery. But confirm the engine will turn over at least a couple of revolution by hand too.

[68+86auto]

Measure the voltage at the battery when trying to crank. Then measure the voltage between the starter terminal and engine when trying to crank. If either goes below 9.6v you will definitely have issues. The voltage should also be within 1v at the starter compared to the battery. On a mini with a good battery and connections the voltage should be much higher.

 

 

I need to get around to creating an interactive diagnostic website. I seem to retype the same answers a million times.

Edited by 68+86auto, 19 November 2024 - 02:19 AM.

[viz139]

You need to clarify shorting the starter on the plus. Did you short the two nuts or the battery cable and spade?  Either way it engaged and cranked the engine so your earths , battery cable and battery are all ok.  You had the starter checked which I presume included the solenoid so your problem is in the circuit from ignition switch to starter white/red wiring including the relay which is in the relay module on top of the servo and also the immobilizer. It sounds like a bad connection or the relay modules are known to suffer from dry solder joints, you will need a voltmeter to determine if the problem is before or after the relay.