Fitting Impulse Sender to HT Leads

[tentonhammer 10]

Anyone got any pics or can quickly take a pic of your 4th HT Lead with Knock sensor fitted? Fitting advice would be equally helpful

 

I've just picked up a new knock sensor from VW and want to fit it asap. Looks pretty straight forward to put on but as my car has never had one fitted (seems previous owner didn't realise the 9A needed one) I've got no point of reference? I just want to be sure I'm fitting it correctly / the right way up / to right end etc.

 

Cheers,

 

C 92 16V 2.0

Edited October 22, 2012 by tentonhammer

[bmwcompact 10]

Sorry but I need to correct your terminology!!!

 

The 2l 16v 9A engine has 2 knock sensors. These are bolted to the front of the block. If pre-ignition (pinking) takes place, these detect this, feed the info to the ECU and the ignition is retarded.

 

There is also an impulse sensor (an ignition reference sensor). This is what you are talking about:part no 051 905 381. Its a small inductive coil through which lead 4 is threaded. It tells the ECU when an electrical pulse firing cyl 4 passes along the lead.

 

I dont think it matters about its position along the lead but I was told that the pointed end of the sensor must point to the distributor. If you have VW leads the connector pulls off the lead-its not screwed on- and it requires effort to remove it. It should then be easy to thread the lead through the sensor. Unfortunately its a tight fit. I resorted to pliers to squeeze the metal crimping on the ignition lead. I have read someone removed then refit the metal crimping.

 

So in theory easy, in practice it seems like you're going to break something!!

 

Hope that helps.

[tentonhammer 10]

Sup BMW,

 

Thanks for the correction! you certainly know your sensors huh?

 

Part Number received was indeed: No. 051-905-381 but is labeled as "HALL SENDER" for some reason? I was under the impression the hall sender was inside the distributor...

 

Part looks correct:

 

[ATTACH=CONFIG]69099[/ATTACH]

 

Pointed end towards distributor - Got it. I heard how tricky these were to install / fit onto HT cable and didn't want to get this the wrong way round!

 

Thanks man

[bmwcompact 10]

Yes right part, and yes the Hall sender is in the distributor. (If you Google 'Hall sender' you'll find that this inpulse sender is also technically a type of Hall sender-its all about sensing current changes/magnetism)

 

Ive never been clear about the function of the Impulse sensor (sender). The car runs without it fitted (I found mine wasn't fitted after months of ownership). Some have said it is the device which tells the ECU engine speed and hence determines how much to advance the ignition. I would have thought that info would come from the Hall sender in the distributor. To me it seems to be a feedback loop for the ECU (a check on whether the ignition is doing as its told).

 

I'm happier with mechanical things, what I cant see I struggle to understand.

Edited August 25, 2012 by bmwcompact

[tentonhammer 10]

I hear you, mechanical - bring it. Electrical - I struggle but get by (lucky enough to have a father and mate who are heavily into electronics!).

 

Impulse sender went on pretty easily, or rather it did after oil and pliers! I see now what people mean when they say it can be a bitch to fit though. Glad I used OEM leads, the end connector popped right off (as the manufacturers said it would) and I was able to slide the sender on with minimal fuss. TBH I was expecting it to take ages! Got it on in 5 minutes ;)

 

A few pics for anyone doing the same:

 

[ATTACH=CONFIG]69115[/ATTACH][ATTACH=CONFIG]69116[/ATTACH][ATTACH=CONFIG]69117[/ATTACH][ATTACH=CONFIG]69118[/ATTACH][ATTACH=CONFIG]69119[/ATTACH][ATTACH=CONFIG]69120[/ATTACH][ATTACH=CONFIG]69121[/ATTACH][ATTACH=CONFIG]69122[/ATTACH][ATTACH=CONFIG]69123[/ATTACH]