Discussion:
9-3 Aero boost problem
(too old to reply)
David Wilson
2004-05-20 09:37:33 UTC
Permalink
One for all you hi-tech people!
Car is an Oct 2001 9-3 Aero HOT Coupe (UK).
Last night it stopped - full set of master warning lights and a horrid
electrical burning smell under the bonnet. AA patrol looked at it, sniffed,
and said "coil pack". Replaced the DI cassette that sits between the cam
covers. (Obviously not a rare problem - he was carrying one!)
Engine starts fine, no more lights, no more smell.
But..... Very little turbo boost (needle goes part way into the orange
band and holds steady under full throttle in any gear.)
Local dealership checked the computer system this morning - no fault found.
Suggested I go away and see if it clears itself. I'm not at all convinced.
Anybody got any clues ?

David Wilson
Tom@saabtech
2004-05-20 11:31:34 UTC
Permalink
Post by David Wilson
One for all you hi-tech people!
Car is an Oct 2001 9-3 Aero HOT Coupe (UK).
Last night it stopped - full set of master warning lights and a horrid
electrical burning smell under the bonnet. AA patrol looked at it, sniffed,
and said "coil pack". Replaced the DI cassette that sits between the cam
covers. (Obviously not a rare problem - he was carrying one!)
Engine starts fine, no more lights, no more smell.
But..... Very little turbo boost (needle goes part way into the orange
band and holds steady under full throttle in any gear.)
Local dealership checked the computer system this morning - no fault found.
Suggested I go away and see if it clears itself. I'm not at all convinced.
Anybody got any clues ?
David Wilson
I am surprised that the dealer gave you that advice, But try this: If you
can find a clear road with an incline on it approach it at about 2500 rpm in
4th gear and plant the throttle and hold it as long as it is safe to do so,
the car will relearn the maximum boost pressure, you may need to carry this
out a few times. If you live somewhere flat like Holland or the Utah salt
flats then you can simulate load by leftfoot braking, but this is not as
successful as when the footbrake is applied the max boost pressure is
lowered. HTH, Tom, Saabtech. [Independant Saab specialist]
Fred W.
2004-05-20 15:25:39 UTC
Permalink
Post by David Wilson
Post by David Wilson
One for all you hi-tech people!
Car is an Oct 2001 9-3 Aero HOT Coupe (UK).
Last night it stopped - full set of master warning lights and a horrid
electrical burning smell under the bonnet. AA patrol looked at it,
sniffed,
Post by David Wilson
and said "coil pack". Replaced the DI cassette that sits between the cam
covers. (Obviously not a rare problem - he was carrying one!)
Engine starts fine, no more lights, no more smell.
But..... Very little turbo boost (needle goes part way into the orange
band and holds steady under full throttle in any gear.)
Local dealership checked the computer system this morning - no fault
found.
Post by David Wilson
Suggested I go away and see if it clears itself. I'm not at all
convinced.
Post by David Wilson
Anybody got any clues ?
David Wilson
I am surprised that the dealer gave you that advice, But try this: If you
can find a clear road with an incline on it approach it at about 2500 rpm in
4th gear and plant the throttle and hold it as long as it is safe to do so,
the car will relearn the maximum boost pressure, you may need to carry this
out a few times. If you live somewhere flat like Holland or the Utah salt
flats then you can simulate load by leftfoot braking, but this is not as
successful as when the footbrake is applied the max boost pressure is
lowered. HTH, Tom, Saabtech. [Independant Saab specialist]
Tom,

Are you sure that will work? I was under the impression that the APC
controller monitors the brake light switch and reduces to base boost during
braking.

-Fred W
Tom@saabtech
2004-05-21 07:12:08 UTC
Permalink
Post by David Wilson
Post by David Wilson
Post by David Wilson
One for all you hi-tech people!
Car is an Oct 2001 9-3 Aero HOT Coupe (UK).
Last night it stopped - full set of master warning lights and a horrid
electrical burning smell under the bonnet. AA patrol looked at it,
sniffed,
Post by David Wilson
and said "coil pack". Replaced the DI cassette that sits between the
cam
Post by David Wilson
Post by David Wilson
covers. (Obviously not a rare problem - he was carrying one!)
Engine starts fine, no more lights, no more smell.
But..... Very little turbo boost (needle goes part way into the
orange
Post by David Wilson
Post by David Wilson
band and holds steady under full throttle in any gear.)
Local dealership checked the computer system this morning - no fault
found.
Post by David Wilson
Suggested I go away and see if it clears itself. I'm not at all
convinced.
Post by David Wilson
Anybody got any clues ?
David Wilson
I am surprised that the dealer gave you that advice, But try this: If you
can find a clear road with an incline on it approach it at about 2500
rpm
Post by David Wilson
in
Post by David Wilson
4th gear and plant the throttle and hold it as long as it is safe to do
so,
Post by David Wilson
the car will relearn the maximum boost pressure, you may need to carry
this
Post by David Wilson
out a few times. If you live somewhere flat like Holland or the Utah salt
flats then you can simulate load by leftfoot braking, but this is not as
successful as when the footbrake is applied the max boost pressure is
lowered. HTH, Tom, Saabtech. [Independant Saab specialist]
Tom,
Are you sure that will work? I was under the impression that the APC
controller monitors the brake light switch and reduces to base boost during
braking.
-Fred W
I did mention that in the last paragraph, but perhaps I should have been a
little more clear. I was trying to suggest a way round the brake light
switch problem but did not want to make it so ovbious as to encorage
somewhat somewhat risky behaveour [can`t think how to spell that], Regards,
Tom.
Goran Larsson
2004-05-20 11:51:33 UTC
Permalink
[cut] Replaced the DI cassette [cut]
But..... Very little turbo boost [cut]
Anybody got any clues ?
The catalythic converter will receive unburnt fuel if one or more
cylinders doesn't fire. Too much fuel will overload the catalythic
converter and it will melt down. With modern cars that have two
catalythic convertes, the first one close to the engine, this will
result in the melted core if the first catalythic converter plugging
the second catalythic converter with pathetic performance as a result.

If you didn't turn of the engine quickly enough when the DI failed
then the probability of a melted catalythic converter is high.
--
Göran Larsson http://www.mitt-eget.com/saab/
David Wilson
2004-05-24 17:01:44 UTC
Permalink
Sadly, you were right - melted cat. Expensive!

Any more uses for a dead cat?

David
Post by Goran Larsson
[cut] Replaced the DI cassette [cut]
But..... Very little turbo boost [cut]
Anybody got any clues ?
The catalythic converter will receive unburnt fuel if one or more
cylinders doesn't fire. Too much fuel will overload the catalythic
converter and it will melt down. With modern cars that have two
catalythic convertes, the first one close to the engine, this will
result in the melted core if the first catalythic converter plugging
the second catalythic converter with pathetic performance as a result.
If you didn't turn of the engine quickly enough when the DI failed
then the probability of a melted catalythic converter is high.
--
Göran Larsson http://www.mitt-eget.com/saab/
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