Ann,
Thanks for posting your ‘results’ to the list. If I were you I would
invest in the Haynes workshop manual for your model also buy a tube of
barrier cream or light work gloves or all three. If your car is not
equipped with the standard Jaguar tool kit, then purchase an articulated
plug spanner and associated ‘Tommy Bar’.
So far the dealer has replaced at least four items of equipment, the first
three of which did not cure the problem. the fourth item, an air filter,
may well have been needed in any event, but was not related to your
troubles.
Cleaning of the Throttle Body, properly executed, is no harm. I hope that
you don’t have any further grief but I wouldn’t be too optimistic. Some
other lister may well be able to explain why a dirty TB would cause the
engine to stall only when the car traverses a rough surface, I can’t.
Among the typical symptoms of a dirty TB would be engine surging when cold.
Improper cleaning of this unit could leave you with subsequent difficult
ies. These would be associated with the Throttle Position Sensor. This
latter device is attached directly to and is normally mounted beneath the
TB. If the operative used a cleaning solvent, especially if applied with/by
aerosol, to remove any build up of oily carbon and allowed any excess
solvent to run ‘downwards’ through the shaft of and into the TPS, then you
are likely to experience additional faults.
If the cleaning method was a simple wiping of the 'Body, with a solvent
moistened rag then it is unlikely that any troubles of this nature will
arise. However if the TB was as dirty as you are led to believe, then the
preferable way to deal with it would be to remove it for cleaning. The
solvent can then be prevented from entering the TPS by the simple expedient
of inverting the 'Body. With the TB off the manifold it allows for easy and
correct setting of the Throttle / Butterfly valve so that the engine will
idle properly.
Be prepared for a reoccurrence of the stalling - watch out at railroad
crossings. If you do encounter this fault again and if the engine does not
re-start immediately, try ‘jiggling’ the TPS electrical connector (plug and
socket). If the engine still fails to start and you have minimal tools in
the car, remove a spark plug and loosen the associated HT lead clips, so
that you can position the ‘loose’ lead and reconnected plug on the engine,
away from the spark plug hole. Place it where you can see the electrode and
whether or not a spark is present when the engine is cranked. That will at
least provide you with some basic information when / if next you have to
depend on the dealer.
Kind Regards,
John Tarrant.
Ann Wrote
<Hi all, especially Brett, Paul and John T. Thanks for your replies
regarding my '91 Sovereign that was dying over bumps, during turns in
front of traffic, over railroad tracks etc. I took it in to the dealer,
and they decided it was a filthy throttle body and air filter, and they
cleaned the fuel injectors for good measure. So far, the car has been
running fine (50 miles and counting), and I’m always happy anytime I can
get away for less than $250 (and with a car wash to boot), but since the
problem has typically been intermittant, I’m still holding my breath for
a while–I had been assuming there was something loose, too. Anyhow,
thought you might be curious how it turned out. Thanks again,
Ann>
), and