Ignition Sensor - Help

[themadprofessor]

Help,

R1100 RT '98 started today after a three day lay up and after about a mile it cut out. I coasted to halt. Typical Hall effect sensor symptoms - Dancing Rev counter and fuel pump running briefly and then stopping.

Tonight I have stripped the buggar down and tested the HE sensor. Trouble is that it seems fine and works as expected. The only possible problem I could see was corrosion on the pins of the connector. One final piece of diagnostic. I had to push the bike about a mile along a busy road to get it home so I had the ignition on with the hazards going..... that is until the relays started going bananas. I decided I did not like this and turned the ignition off. Battery is one year old but OEM type and I do occasionally get the alternating ABS light syndrome on cold mornings.

Tomorrow I shall reconnect the HE sensor. Has any one any other suggestions on what to check before I reassemble the machine.

Thanks Chris

 

[Tarka]

Are you sure the battery connections are tight,and free from corrosion? If it`s a lead acid battery is the electrolyte level correct? The occasional ABS failure to reset is endemic to the breed.
If you haven`t got one,get an Optimate.

 

[themadprofessor]

The battery was a little low in electrolyte and I topped it up a few weeks ago. I suspect that I might have overfilled it and diluted the acid as the ABS light problem only started after this. However I don't think that is the problem. My son's ignition sensor went a few months ago and the symptoms were similar with the dancing rev counter and no go. The only difference on my bike is the stopping and starting of the fuel pump. I think from memory that the Moronic turns the fuel pump off until it gets a stream of pulses from the ignition sensor indicating to it (the Moronic) that the engine is rotating. I was just worried as symptoms like this could also be caused by the Moronic losing its last brain Cell .

I am praying that it is not that as I definitely can't afford that......

Chris

 

[Tarka]

You won`t dilute the acid,unless perhaps you put a litre or two of water in.......

Moronic ??? Time for 'T' methinks...

Hmm,interesting fault....

 

[Frank Warner]

Gental heat to the hall sensors - use a hair dryier while someone is not lookin.

The hall sensors usually start to fail with heat, then come good when cold. If they fail out on the road a bucket of water should dumped over them should cool them down enought to make a few blocks. Aim for a pub.

 

[themadprofessor]

Update - Latest findings

I went out tonight and connected my LED tester, however the Rev counter madness and continuous clicking ETC continued. So I pulled a spark plug and noted that it was damp with fuel. Then when I switched the ignition back on an almost continuous stream of sparks occurred in time with the clicking. I now think that the clicking I was hearing was actually the injectors triggering.

I moved the fuel tank backwards and tried my LED tester in the HES socket; however by now the thing had stopped the craziness and when I cranked the engine over I just saw a blicking from the LED. I did notice that the LED was really quite dim on both sensor outputs compared to it's brightness when attached to the 12 volt feed terminal.

I then tried and eventually managed to get a reading from the Motronic fault readout. The LED would not give me a reading whilst the madness was happening. Eventually the thing seemed to settle down and after several goes I was able to crank the engine without starting or get the bouncing rev counter and clicking noises. It wouldn't start but afterwards I got 1133 as a code. I tried several times but this was the only fault code I could get out of the Motronic.

1133 is I believe Hall signal 2 so I suppose I have to accept that the HES is bad. I am going to try and borrow a known good s/hand one in the next couple of days and try that. I will let you know how I get on.

Thanks for all the hints and help chaps!

Chris

--------------------
'98 R1100 RT

 

[themadprofessor]

Final (I hope) Update.

Tonight I have installed a HES that I got from my son's spare RS. The bike runs, I went over to my son's house with the bike unclothec to get his help in replacing the plastic Alternator cover which I find a buggar to get back on myself. Bike seemed fine. I have just replaced all the fairings and will test tomorrow.
: :


So it seems that the HES was defintely bad even though it passed my LED test........

I think I will strip the old one down, and replace the HES sensors and cable loom and have it as a spare.

Anyone ever managed to change one by the roadside with the BMW tool kit?????

I hope this second hand one willl last at least as long as it takes to rebuild the old one.

Thanks for all the help

Chris

 

[ebbo]

I’ve run a repaired ignition sensor assembly for well over 12 months now, no problems.