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Now as to
why the Ignition failed, the following come to my mind:
1) That the Ignition Coil overheated for some inexplicable reason.
2) That the Spark Plugs were ‘over-gapped’ and couldn’t
fire under the higher load/Cylinder pressures the engine was subjected to
under the circumstances.
3) The ECU’s of Mpfi Cars have an ‘over-voltage’ sensing/cut-off
feature, to protect themselves under such conditions from permanent damage.
This ECU feature in Kim’s case may have reacted to a momentary mal-function
of the Alternator Voltage Regulator producing voltages higher than 15. This
is plausible, as the Alternator in an M800 with the VR inside it is located
close to the red-hot running Exhaust Pipe – then running hotter than
normal under the enhanced load that the engine was subjected to.
4) Once the Engine cooled-off, both the Ignition Coil and/or the Alternator-VR
regained their ‘consciousness’ – permitting the engine
to fire as usual.
5) As to why the Car didn’t start when attempted to be push-started,
even in reverse gear, well it’s the peculiar characteristic of Mpfi
Engines – necessitating that they be ‘Jump-Started’
only using another Car/Battery and push-starting is advised against.
6) It’s the latter bit that is important in Mpfi Cars as otherwise,
the ECU is unable to take a correct stock of the total situation, including
the desired manner of energising the in-tank high-presure electric fuel
pump, and issue the right engine starting sequence of commands.
Interestingly enough, Suzzanne reported another such ‘stall’
after nearly 6-months of the first one around midnight on a full moon
(again!), but this time in the heart of Mumbai. This time there was a
subtle difference though – the Car just didn’t die down but
‘coughed and spluttered’ pretty roughly and attempts to restart
it resulted in similar cough-outs!
According to her, they were lucky to be able to get hold a ‘not
so friendly a mechanic’ at that hour who – a) disconnected
the fuel pipe in the engine bay and blew/sucked into it and b) removed
the rear seat, ‘did some thing’ and viola – the car
started in the first crank – purring away as usual!
Even upon asking point blank, the Guy wouldn’t part with his trade
secret. So back to me – what was it this time ?!
 Well, the answer
according to me is simpler this time than the previous one. If one goes
back to ‘Some basic reasons behind stalling of a running engine’
– points 1&2 above, the way it died this time (sever coughs
and splutters) clearly points to a fuel supply failure from the in-tank
electric fuel pump in such Mpfi’s. And it happened coz of a loose
contact at the ‘coupler’ to the Fuel Pump – which the
Mechanic ‘refreshed’ by lifting the rear seat of the Car as
it’s located under it !
Well that’s all at the moment that I can think of. Any other bright
sparks are welcome to brainstorm with me !
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