#BDR Wiring, ballast-resistors and types, Lucas 43D Distributor, blanking plate, Pertronix electronic ignition and coil, covertly damaged dizzy cap: no spark

This is my journey that concluded with discovering the inside of my BDR Distributor cap is/was catastrophically damaged and the cause of my sudden "no spark" problem after engine switch off - basically I broke it and did not look inside the dizzy cap.

It covers:

Tracing the ignition wires when ignition key connections are all taped tight and inaccessible and I don't want to undo everything:

https://www.caterhamlotus7.club/forums/topic/276076-wiring-digram-for-1987-bdr-or-where-do-the-two-wires-from-the-coil-go-once-inside-the-loom-solved-much-ballast-resistor-content/page/2/#comment-2617144

Following the above exploring ignition ballast-resistor prsence of not -not realising the one on the master circuit is NOT the same as having one in the ignition circuit:

https://www.caterhamlotus7.club/forums/topic/276126-ballast-resistor-or-not/

Realisation having a ballast-resistor  in the master circuit is not the same as having one in the ignition circuit:

https://www.caterhamlotus7.club/blogs/entry/1044-ballast-resistors-more-than-one-type-i-just-discovered/

Considering replacement of the whole distributor with one that has vacuum advance (DistributorDoctor.com)

Lucas 43D means it is a Lucas 45D WITHOUT vacuum advance.

https://www.caterhamlotus7.club/forums/topic/276137-bdr-cosworth-cams-fitted-in-1987-what-were-they-what-spec-290-degrees-duration-solved/#comment-2617506

So in conclusion I have ordered replacement parts as follows

From DistributorDoctor.com Contact "Martin"

Side exit Distributor cap for Lucas 43D, 

Clips of the original design,

From pertronixeurope.com Contact Mark

improved rotor arm (also available from Distributor doctor), 

Pertronix ignitor version 2, 

Matched coil which has a primary resistance of 0.3 ohms 

New “blank“ which fits inside the distributor and provides a locating feature so the cap will not move, it "blanks" off where the vacuum advance would be.

and I have been given advice on how to fit the dizzy wiring rubber Grommet (involves using silicon grease or fairy liquid), this is very difficult to get at under the BDR (Dellorto 45 DHLA C) carburettors. 

Another suggestion is to remove the carbs not at the manifold/carbs interface but at the inlet manifold to block interface, and I have now found I have new gaskets (a pair) in my stock so will reconsider this tactic. BurtonPower.com want £8 to post a gasket even within GB which is ridiculous.

With my thanks to those very patient contributors to the above threads as I struggled through being completely perplexed why one second I had spark and the next none. What had happened was while installing two Colortune plugs I had tugged on the HT Leads and this dislodged the distributor cap such that the spinning rotor arm destroyed (see image)  two of the internal contacts of the cap. I idid not notice this damage until eventually looking inside the cap. Throughout all of this I had the feeling I had physically broken something, and there it was. 

Special thanks to mike7 who spent an hour on the phone with me at nearly midnight and caused me to look inside the dizzy cap.

As a result I have deferred changing my Lucas 43 D (no vacuum advance) to one with vacuum advance (i.e. a (like) 45D) to a later Winter project date as originally contemplated.

Update: while I replace the rotor arm as a matter of course I just discovered it too is damaged inside, the little bit that locates it is damaged to the extent any pressure on it when in place causes the rotor to lose it's grip on its position, so in other words this explains why no spark at all, not even from the two cap contacts that are not damaged. The image shows an undamaged one and the damaged one. The damaged one will locate correctly, but as soon as I apply a little turning force with my fingers it lets go.

Anthony

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