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Re: TR8 ignition/Lumenition

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Re: TR8 ignition/Lumenition
« on: May 13, 1993, 01:21:23 PM »

Jim says:

>  What *else* could keep the car from not starting when you've got gas and
>  spark and the correct timing?  Anyone?

What indeed, sounds like it should run.  I havn't had the full thread described
to me but I would ask:

1.  You hear the injectors fire, but how do you know how much fuel they are
metering?  What's the injector system?  I have a Bosch LE2 on an in-line four
and there's no way you can start a warm engine when the coolant sensor doesn't
work for instance.  You can still hear the injectors fire of course.

2.  How do you know the spark timing is correct?  Have you looked dynamically
with a spark triggered timing light?  (When turning over on the starter motor
of course since your engine won't fire.  Note that the timing light may not
work when the battery volts drop as the starter motor turns).

3.  When the car "eventually did [start] later", how did it run......?

4.  This may well be important: Most injection systems run 'open loop' _until
the engine fires_.  When it does fire, the computer takes over full control.
This has the effect sometimes that an engine will fire initially but not run if
you have a control box fault or sensor fault...........  Typically fuel
pressure is enabled during cranking whatever the sensor conditions; when the
engine fires however the computer needs to be happy for pressure to remain
enabled.  Just one of those little safety features that makes fault finding so
much fun!


Hope this helps
Steve.