[modern] Deathly Hush - CPS problem?

Motoring serenely along a country lane at 40 'ish mph behind a line of cars
with the trans in “sport” mode, ready to surge past at the first opportunity,
I eventually abandoned the idea when that opportunity never presented itself
and returned the trans to normal mode. The trans immediately changed up a gear
with a slight jerk [most unusual] and the engine stopped - not stumbled, not
missed a beat, not hiccupped, but went deathly quiet just as surely as if I
had switched it off with the ignition key.
The rev counter dropped to zero and the battery and oil lights illuminated
momentarily but the engine fired again just before the car would have rolled
to a halt. It then ran sweetly again for another couple of miles until I was
amongst traffic in the narrow streets of the next village - and then quit
again in the same manner, except that this time we came to a grinding halt.
On neither occasion was there a “Check Engine” warning or a VCM failure message.
With as much aplomb as I could muster [there were people staring and little
kids pointing] I nonchalantly raised the bonnet and wiggled all of the
connectors on the CPS and all the sensors, smiling at the other motorists who
were struggling to squeeze past my car in the narrow street. [Aren’t some
drivers rude ?].
Back in the car, turned the key, instant start, ran as sweet as ever and has
continued to do so for the rest of today. Checked for VCM codes again [because
Haynes says that you can have a code without the “Check Engine” icon
illuminating] but nothing showing as stored in memory.
Checking the archives I can’t find the specific reference I’m looking for
[amongst the 482 CPS entries!] but I seem to recall a similar incident where
the fault was found to be a duff [intermittent] CPS. Am I correct in thinking
that a flakey CPS or it’s wiring will not give a “Check Engine” warning but
simply cut off the fuel and sparks ? [I didn’t have the opportunity to check for either of course because the fault cleared itself].
My theory is that the slight “jerk” when the trans changed gear when I came
out of “sport” mode somehow disturbed the CPS connector / wiring as the engine
rocked on it’s mounts.
I have a spare new CPS which I will now fit anyway [and at the same time fit
the blanking kit for the redundant SLS hydraulic pump which I haven’t got
round to installing yet].

But, could it have been anything else ?

Bryan N
�91 4.0 Sovereign [76 K]
�91 1.6 MX 5 / Miata [87 K]
Cambs., England.

The CPS has no VCM codes.
That is likely your problem, and maybe the harsh trans shift
had some effect on the connections…

I don’t think its LIKELY an internal sensor problem would happen during a
harsh shift, but on my car, the CPS wires are tied to the radiator hose,
and since the engine moves on its mounts, but the radiator does not,
there could be force on the wires/connector.
There should be plenty of play in the sensor wires to prevent them
being tugged on when things move around and expand/contract with engine
heat and movement.

1990 XJ6