Post
by PeterCrespin » Mon Mar 30, 2020 3:21 pm
This has been (continues to be) an interesting thread in terms of decision-making and other aspects that relate to market making, medical diagnosis, trouble-shooting in general and even relationships. Since we're all stuck indoors, it might be worth a sideways look.
The title of the thread says where Andrew was coming from as a three-time 123 user. He began(lightly edited):
“I decided to replace my fully-rebuilt Lucas distributor, leads and coil with a 123 and to be honest she has never run perfectly since. There have always been intermittent misfires for apparently no reason.”
Call me old-fashioned (© M. Hermaszewski) but there are three logical reasons: 1) Faulty part(s) and/or 2) faulty installation and/or 3) faulty service conditions. Occam’s Razor applies and none of the above involve fuel.
“….it’s reasonable to say I have had one or two OK-on-all-6 experiences, but most of the time I have a misfire.”
Depending on how you define ‘OK on all six’, it appears that 1 and 2 can be set aside temporarily, since faulty electronic ignition or bad installation would tend most often to result in failure to proceed or consistent bad running. Plus Andrew has fitted 123s before. We might have to come back to them later if 3 turns out to be wrong. There’s still no need to add complexity and start thinking about a simultaneous fuel issue, at least not yet.
“The 123 does seem to be pretty sensitive to lots of outside influences. Can anyone shed any light on similar experiences…?”
Indeed they can. Several listers agreed with you. In their estimation the 123 is “pretty sensitive” as you correctly put it, to electromagnetic/RF interference in cars running non resistor plugs. You further wrote:
“There is no doubt that one downside of an electronic ignition is they seem far more sensitive to resistances etc.”
“I am beginning to think the issue is going to turn out to be the lack of resistor plugs, thank you David for the above.”
“I need to revisit all my connections and fit my soon-to-arrive resistor plugs.”
Bingo. Looks like you have your answer and you make the next logical move by ordering the correct plugs for an E-type running a 123 It is highly likely that the plugs will fix the problem, but even if they did not on this occasion, their fitment is the wise thing to do and would help avoid future sensitivity problems if, say, a marginal connection crept in somewhere. Fitting the plugs you just bought is a no-brainer. Job’s a good ‘un, but no – spoke too soon.
When you took them out, the misfiring engine’s plugs smelled like your dad’s “sheds full of old vehicles that had not run for years.” Your car is like new and had a good run down to Goodwood a few months ago on the same tankful, and is stored in a dry garage. Nevertheless, smell is indeed one of the primal senses and it has clearly 'sparked' a handbrake turn in a new direction that risks the massive traps of observer and confirmation biases (which is normal, not a personal attack, Andrew).
It will be a useful lesson for us all, however this works out. I have no insights to offer regarding your particular car, and sight unseen (or 'tank-un-sniffed') it's quite possibly nothing to do with ignition. The problem is you have spelled out correctly the key factors that spell out why that's a favourite first guess and are now describing things that argue against your initial view. This happens to us all sometimes if we think around some subjects. I am interested in the process by which the eventual solution is achieved. It would be boring and we’d learn little if we all thought the same way. One person’s snatching defeat from the jaws of victory is another person’s creative leap forward. Please keep us posted! Since the Grand National is off, maybe Angus could run a book?
1E75339 UberLynx D-Type; 1R27190 70 FHC; 1E78478; 2001 Vanden Plas
