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View Full Version : Misfire...


Nick.Hay
12-03-2007, 08:21 PM
Right...

18 months ago, I had an issue with misfiring in my 535i.

I was told to replace the ignition leads, which were expensive, and as a result of me being a broke student with two hungry cars to feed, I decided to take the E34 off the road.

Today I bought and installed new ignition leads. When removing them, this is what I found:

http://i18.photobucket.com/albums/b104/stnick/04122007676.jpg
I'm not entirely sure what this thing does, but it was completely snapped off the ignition lead loom.

http://i18.photobucket.com/albums/b104/stnick/04122007677.jpg

This is where it plugs in on the engine
http://i18.photobucket.com/albums/b104/stnick/04122007681.jpg

Which is there, in the scheme of things
http://i18.photobucket.com/albums/b104/stnick/04122007682.jpg
Nick.Hay
12-03-2007, 08:22 PM
It also looks like there were plug lead issues in the car's history too.. Note the insulation tape!!
http://i18.photobucket.com/albums/b104/stnick/04122007678.jpg

More here
http://i18.photobucket.com/albums/b104/stnick/04122007679.jpg

I'm yet to take her for a run today... But hopefully the new leads have cured the issue!! :\


On a lighter note... These arrived today!! Yay... Angeleyes ;)
http://i18.photobucket.com/albums/b104/stnick/04122007675.jpg
Torque
12-04-2007, 01:52 AM
It senses when there is spark in that lead; the ignition system gets a signal/pulse and uses that as a reference point for the firing ... I'm having a hard time thinking up of a correct way to describe it right now. Maybe someone else can better.
Ferret
12-04-2007, 02:28 AM
Yeah, as torque says - it's an inductive pulse generator for the ECU to take a reference signal for the exact moment of ignition/firing.

Without it, your engine will have been running in crappy open loop defaulted mode...
Nick.Hay
12-04-2007, 03:15 AM
Took it for a short run to the "workshop" (a mate's tiny single-car garage), and it felt instantly better!! Maybe it was a bit of 'freshly washed car syndrome' but, I think there was an improvement. Can't wait til she's all serviced, rego'd and detailed, and back to her lovely self again!! :D :D