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3.5 EFI ignition wiring - Duh, Whats Missing?


joe1
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Bought quite a clean D plated 3.5 range rover as a non-runner, just starting to investigate but have found some 'interesting' things (and excuse my numptniness on such matters but I don't know v8's at all). These look wrong even to a numpty like me....

1. The 3-pin 35DM8 dizzy (here)

008_zpsubuiufpu.jpg?1473516881312&147351

is exactly as you see it - not connected to anything at all - and there is no cable anywhere to be seen - someone's nicked it?? What I need to know is where should the three terminals connect to? I've found somewhere that pin1 goes to coil -ve, pin 2 is spare, and pin 3 is coil +ve, but which is pin 1 and which is pin 3 in the picture?

2. The other problem is that the coil only has one connector on it:

002_zpsd6kvzdn2.jpg?1473516881312&147351

That white cable you see on the +ve side goes into the loom. There is also a (disconnected) white cable that I presume should go to -ve side of coil (Correct??), which goes into another part of the loom near a relay - which some butcher has also had a go at:

006_zpsdwua7zra.jpg?1473516881311&147351

I'm guessing but the relay could be the overrun relay (?) - and the butcher seems to have attempted to bypass it by making direct connection between the coil -ve and a blue/white cable that goes, guessing to the tach/ecu. 

Once I can restore these cables to the right positions I'll then be able to carry on and do some tests, but I don't want to b*****r up anything before that point

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Cant remember the dizzy wires but it seems it is quite common to bypass that relay, mine was like that (slightly tider wiring though) before I put a MS in it. There was also a little inline resistor on the coil that yours seems to be missing. I think the tach is run of an alternator signal on these. There should be a power wire to the coil that is live when the ignition is on, makes it easy to figure out which one

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Cheers Cheesy, yes the inline resistor was actually on the end of the cable that wasn't connected to the coil so at least that bit's ok. The answer to the polarity question seems to be that the left-most pin looking down as in the first photo is to coil +ve, right-most is to coil -ve and middle is unused. I found this on another forum see (http://forum.lro.com/viewtopic.php?f=21&t=30915). However I'll probably have to get hold of a proprietary connector anyways, but at least now I'll know how to double check the polarity of the wiring. On with the testing then....

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The other thing to consider with this, is that the reason it is not running could well be that the ignitor on the distributor has died, it is pretty common (I bought mine not running with exactly the same problem and replaced it with a Jaycar universal ignitor). There was also a kit to relocate the ignitor near the coil so it doesnt get hot 

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Thanks guys, yes I bought a cheap ignition module with the new 3 pin converter lead, thinking that a failure was quite likely in that component. And yes, ultimate solution is to re-locate the thing away from heat source. I've only just got the new cable so on with testing today if the rain ever stops.

I bought these bits from these people http://www.simonbbc.com/shop/images/V8_instructions.pdf, but tbh it al looks a bit shoddy - the terminals on the lead weren't properly seated in the plug so one wouldn't contact properly, I had to dis-assemble and correct, and the ignition lead has no ground pin - they will probably say that it grounds through the distributor. And there's no heat sink paste for fitting the ignition module either, so will source some suitbale dialectric grease or something (and how will that  affect grounding of the ignition module...)  .

And *****CORRECTION*** to my earlier post on above on polarity above - its the opposite way round to what I said according to the aftermarket suppliers info - so left most terminal is -ve coil rightmost is +ve - just in case someone else looks fro the same info!  

 

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1 hour ago, Davo said:

You need proper heatsink paste to keep the module from overheating. A dielectric grease will probably just insulate it, and you don't want even more trouble with the thing. 

good point, something like this one perhaps, maybe

http://www.maplin.co.uk/p/servisol-high-thermal-conductivity-heatsink-compound-n57al?cmpid=ppc&gclid=Cj0KEQjwsO6-BRDRy8bsxfiV2bkBEiQAF8EzKDcFlrVkYbtrbIwQXLGWWbul6f6BEYqJU70U9NUd1icaAhiw8P8HAQ

 

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