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HT Leads

Posted: Tue Mar 18, 2008 12:55 pm
by TRANSPORTER
Just a quick one, the sensor that is attached to the HT Lead, how exactly is this sensor attached, just asking because if it is possible to remove and refit the sensor onto another set of leads then this is what I want to do, due to the high price of a new set of leads for a six cylinder M20, has anyone attempted this or will I have to stump up a minimum of £75 for a set of new leads, if anyone here knows of a better price please let us all know as I find the price for leads pretty hard to swallow, especially as you can pick up loads of others for a much cheaper price and of the same quality.

Re: HT Leads

Posted: Tue Mar 18, 2008 2:00 pm
by zaust
You can leave the sensor off fella.

Re: HT Leads

Posted: Tue Mar 18, 2008 2:07 pm
by andyaskew
What does it do?

Re: HT Leads

Posted: Tue Mar 18, 2008 2:12 pm
by George_Of_The_Jungle
What sensor?????? i havent really bothered looking at my leads. How much do GSF charge for leads?

Re: HT Leads

Posted: Tue Mar 18, 2008 2:15 pm
by wullie325i
on one of the leads theres an extra lead that attatches itself to it like a ring around the lead and im sure it goes to the throttle body but cant remember for sure and i think its a pulse sensor or something like that

Posted: Tue Mar 18, 2008 2:18 pm
by wullie325i
Image

the extra lead is there at the bottom right

Re:

Posted: Tue Mar 18, 2008 2:21 pm
by wullie325i
but like marc said you dont need it though

Re:

Posted: Tue Mar 18, 2008 2:22 pm
by George_Of_The_Jungle
Goes around a lead? sounds like a hall sensor (senses electro-magnetic fields) could it be something to do with the ecu, obc or a check panel. bmw dont seem like the ppl that would put a useless lead on the set just to charge ppl more money. it must do something?

Re:

Posted: Tue Mar 18, 2008 2:25 pm
by wullie325i
it will do something but im not sure what and i know that it dosent make any difference to the running of the car.

most high performance lead sets dont come with them either although you can request them at an extra charge.

Re:

Posted: Tue Mar 18, 2008 2:28 pm
by zaust
Diag back to the ecu...

Re:

Posted: Tue Mar 18, 2008 2:32 pm
by wullie325i
zaust wrote:Diag back to the ecu...
what does it do marc i dont get what you mean? :(

Re:

Posted: Tue Mar 18, 2008 2:44 pm
by march109
wullie325i wrote:
zaust wrote:Diag back to the ecu...
what does it do marc i dont get what you mean? :(
Sences electical current in the HT lead and hence plug sparking and sends a signal back to the ECU.

Re:

Posted: Tue Mar 18, 2008 2:56 pm
by TRANSPORTER
ok guys Ive just PM Mr Brianmoooore, to get the diffinitive answer on this subject, I have heard that you can run without it but knowone that I know of has actually done it to my knowledge, if it slides off then i can make up my own leads and slide the sensor back on to the new lead and bobs your uncle 7 new lew leads at a fraction of the cost. fingers crossed, will have the answer on this thread when I hear back from the oracle that is Mr Moooore.

Re:

Posted: Tue Mar 18, 2008 3:00 pm
by zaust
I don't run one on the tech 2. the mummy wagon or my tech 1 touring with later loom. All fine and dandy.

Re:

Posted: Tue Mar 18, 2008 3:07 pm
by Brianmoooore
It's effectively the cam position sensor, and the only way the ECU knows which of the two cylinders that are rising up the bores at any one time is on its compression stroke and which is on its exhaust stroke.
On early versions of motronic, it just connects to the diagnostic socket, but on later versions it feeds the ECU as well.
Engine will run without it, but marginally better with it.
Why are you changing the HT leads anyway? I've NEVER changed an E30 HT lead that wasn't physically damaged. I've tested plenty, and never found any deterioration.
Running on LPG is an excellent detector of inadequate ignition components.

Re:

Posted: Wed Mar 19, 2008 9:34 am
by TRANSPORTER
Many thanks Mr Mooore for your quick response, I,m changing the HT leads because my number six cylinder lead broke its insulation rubber around the plug, just deterioated over time I suppose the rest seem to be ok, but for pure piece of mind I would like to change all of them to make it a proper job and not a bodge if you know what I mean. I will look under the bonnet today to see where the sensor lead goes to, ie if it runs to the diagnostic plug or into ecu.

Re:

Posted: Wed Mar 19, 2008 9:58 am
by --alpina--
i haveK1 performanceleads as you can see below in the pic and i didnt notice any difference and also have contemplating to cut that bit of HT lead from one side of the ring end and take off carefully to fit using little silicone glue to hold it in place on to my new lead set but never got around it...


j

Re:

Posted: Wed Mar 19, 2008 12:41 pm
by andyaskew
I just bought some from eurocarparts

HT Leads, Distributor Cap & Rotor arm = £140 :?

Re:

Posted: Wed Mar 19, 2008 12:58 pm
by Pyros
ive just changed my spark plugs and the ht leads seem to have got the tops of the old spark plugs stuck in them any ideas on how to remove them?

Re:

Posted: Wed Mar 19, 2008 1:38 pm
by Simon
Pyros wrote:ive just changed my spark plugs and the ht leads seem to have got the tops of the old spark plugs stuck in them any ideas on how to remove them?
Remove the heads of the plugs, and they will fit fine.

Posted: Wed Mar 19, 2008 1:40 pm
by e30325itourer
when you say tops do you mean the bits that screw off the top of the spark plugs if so they should not be fitted on the plugs

Re:

Posted: Wed Mar 19, 2008 1:48 pm
by Pyros
cool thanks guys.

Re:

Posted: Wed Mar 19, 2008 1:54 pm
by TRANSPORTER
You see even £140 quid is steep even for what you bought andy, and I think that you and I alpina have the same idea with the removal of thre sensor and then attempting to put it on to a new lead.

Re:

Posted: Thu Mar 20, 2008 12:01 am
by Brianmoooore
Get a replacement lead or leads from a scrapper, and the problem will be solved.
Even the few I've replaced have all been replaced by good second hand ones.

Re:

Posted: Thu Mar 20, 2008 9:03 pm
by gaszman
juat paid 74.90 for dizzy cap rotor arm and pluge she runs better than ever now cant beleive i didnt do it sooner .
now when i throttle through to the red line she pulls no hesiation or nothing great :twisted: