Yeah, I figure I'll put it in and see what happens, though when the codes were checked nothing seemed amiss with it.
Anyway, once it's in, if the miss-firing returns, I'll just disconnect it again and leave it be unless something 'orrible starts happening.

it is a strange thing, the cam sensor would be mainly used in engines with sequential injection, eg; au.
but ef has the wiring and the cam sensor for sequential yet it still runs batch fire on the injectors, (123) in one batch and (456) on the second batch..
the ecu uses the cam sensor as a reference to where compression stroke is for injector cycle,
so imo worse case scenario is if it dont see a cam sensor it may by default fire all 6 injectors every cycle, which is what some aftermarket ecu's do...

That makes sense - in practice with it unplugged the engine feels and runs absolutely same as before - but without the bugbear random shuddery miss - which is GREAT!

"worse case scenario is if it dont see a cam sensor it may by default fire all 6 injectors every cycle, which is what some aftermarket ecu's do..."

You means sending fuel into the combustion chamber when it's not ready to fire? This would cause miss-fire/using heaps of fuel?

If so, could that be that the problem with our sensors - occasionally going into default?

wouldnt be a big issue, as they are the injectors fire no 123 at once and 456 at once even though its only one of those cyl that is being fired. so any excess fuel will be consumed and burnt on the next cyl cycle, the o2 sensor will or should make changes if it sees a richer mixture than normal ... if anything you would have a slight cooling effect on the valves from injectors batch firing..

In my case, the issue I was having was ONLY the intermittant / random hiccuping miss - otherwise my engine was running fine and idling good along with normal to extremely good fuel economy depending whether I was using XR6 ECU or STD GLi ECU - and when I disconnected the CMP sensor there was NO CHANGE whatsoever to any of the other running charactersitics of the engine apart from the hiccuping / miss disappearing.

From that I think that either the engine DOESN'T default to full bank fire at all - or if it does, then functionally the result is no different to when it's running "normally" - so it isn't an issue.

As far as why / how the sensor being connected can be causing the miss - and not registering codes - i think in my case my aux shaft gear and crank gear aren't lined up properly - so the phase signal maybe goes outside the tolerance the ECU can cope with - but not all the time - I suspect it's under certain load / rpm conditions - and when that happens, there's a general hiccup thru the system and injector and ignition timing are momentarily lost. No codes is probably down to that particular fault not being anticipated so therefore not being captured.

With no CMP signal at all the ECU probably logs a missing CMP fault code but otherwise just carries on. If it also switches to full bank fire then as I say, it evidently ends up functionally no different to normal mode.

I've been revving mine out to redline and covering the full load range since having the CMP disconnected and I haven't run into any peculiarities or loss of performance - and I'm also running quite a big cam (takes 3.4mm of extra shimming on top of the single factory shim to keep it from rattling) which I think would amplify any irregularities.

Well, after all that, the new sensor arrived today.
As for installing the thing, all the manual says is 'go see a ford centre'.
It's obvious there are just two screws to undo to remove the old one, and replace it with the new one...but does the shaft need adjusting?
I have a timing light (if any use), or is it a job for a (shudder) mechanic?

the engine needs to be tdc on compression stroke cyl 1, there is a small hole on the cam angle sensor to put a small alen key or nail to lock it in its tdc trigger position, then you simply fit it to the engine so the base is in the right position for the stay bracket, lock it down and remove the allen key or nail.....

My sensor didn't come with a small hole anywhere, just the two holes for the screws.
And...I saw my mechanic when I dropped in my coaster for a service, and explained the situation, and he reckons if it's working, and others have left it unplugged without a problem, I should leave it unplugged.
That's the state of play so far...I have yet to hear any issue with it unplugged. If it's just a matter of undoing two screws and taking the old one off, I'll do it just to see if it WAS the senor. But, if I don;t need to...
What an ungodly f***around for 'an occasional missfire'!

If you are just replacing the black,round part on top of the camshaft position sensor/synchroniser,,then just disconnect the electrical connector and undo the top 2 mounting bolts and lift out sensor and replace with new one.No need to set engine to no.1 cyl at tdc unless you are changing the whole sensor assembly.Good idea when you have the top part removed to check if sensor shaft has excessive play in it as this may indicate worn/damaged sensor drive gear or worn/damaged auxilary shaft gear.

as above,
i thought you were changing the whole assembly....

Ah, my mistake.
Just the top section. I'll replace it then, and check for shaft play.
Many thank for the help.
Still have the mouse running around.

Just an update; had a mini-seachange and bought myself a bus to live in (1990 Toyota Coaster - great machine!).
I'm living in it now, actually. Pretty basic atm, but really lovin' it! Drive to a nice spot, park, and enjoy the serenity!
Anyway, the car is up for sale. See the For Sale forum.

Lucky bloody you!!!

Finally sold the car after advertising locally (parked it on the highway).
Many, many thanks to everyone here who helped me with any questions over the past year; a great site and forum for any ford owner, and one I'll recommend.
I'm now living in the toyota coaster, so (for now), my ford days are over.
Once again, thanks.