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Discussion Starter · #1 ·
I was having a look in the Haynes repair manual and noticed that it says during "sharp"
acceleration the boost guage should briefly go up into the red. My guage never really goes above the middle area. Any ideas as to what is causing this?

BTW : I have a 1991 9000 CD turbo. Thanks in advance.
 

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Is yours an automatic?

Mine is, and there seems to be some kind of mapping in the ECU as to how much boost is available at what speed etc. As far as I can tell it is aware what gear you are in as well.

For example, if I'm doing 20mph in 2nd and floor it, the boost winds up very quickly to about 4mm shy of the red section but no further. As it hits about 45mph "the shackles are lifted" and the boost goes more or less exactly to the further orange/red barrier line.

*Sometimes*, and I can't find any kind of pattern to this, when the boost is freed, it bounces maybe 5mm into the red for a second before catching itself and going back to the red/orange barrier.

Not sure if there is a pattern, or maybe mine just has a sticky wastegate, or maybe it's by design...

It does make for quite interesting overtaking from slow speed (tractors/cyclists etc.) as I find just flooring it makes it quite a handful. When the boost comes onto its second stage it's quite a kick. I always find it easier to wind the throttle up smoothly than just boot it...
 

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 My guage never really goes above the middle area.[/b]
Firstly the car adapts to altitude etc.. so it may perhaps nip into the red at sea-level and less if at high altitude (if everything is working top notch) but most likely the needle will just fall soft of the red in the broken area of the gauge.

When you say the needle never goes above the middle area, do you mean the needle never clears the middle of the centre orange section of the gauge?

If that's so then you are perhaps only running at base boost. In which case the obvious reasons for that are - A vacuum line has fallen off somewhere, the wastgate actuator rod has slipped of the wastgate or an APC solenoid problem.
 

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Discussion Starter · #4 ·
It's an automatic . That sounds very different from how my car performs. I'm wondering if there is some kind of leak.

MarkA : It does inch past the middle a bit, but it's never gotten near the broken area of the guage.

Thanks for the responses , I'll have a look around for (more) vacuum leaks and a disconnected wastegate rod.
 

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If it's never got near the broken section of the guage, then I'd definately say it's running base boost. Have a good lok at the hoses and test the APC solenoid by the radiator. Best way to do this is turn the ignition on and then pull the plug off the top, it should click, and then click again when you put the connector back on.

Neil
 

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Originally posted by Neil(CS2.3T):
[qb]Best way to do this is turn the ignition on and then pull the plug off the top, it should click, and then click again when you put the connector back on.[/qb][/b]
Does that work for the BPC valve fitted to DI cars? I was under the impression that it only worked for the pre-DI/APC system.
 

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Discussion Starter · #7 ·
Anyone happen to have a picture of the APC solenoid? (a description of it will work too). I can't seem to find anything about it in the haynes manual.

-- Just read BillJ's post. I'm guessing the BPC valve replaces the APC solenoid on my car? I had located a BPC valve before, but didn't know if the APC solenoid was a seperate part.
 

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Originally posted by BillJ:
[qb] QUOTE
Originally posted by Neil(CS2.3T):
[qb]Best way to do this is turn the ignition on and then pull the plug off the top, it should click, and then click again when you put the connector back on.[/qb][/b]
Does that work for the BPC valve fitted to DI cars? I was under the impression that it only worked for the pre-DI/APC system. [/qb][/b][/quote]You're probably right Bill, I wasn't thinking DI when I wrote that, but I'll check on one of mine tomorrow out of curiosity.
 

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hello,
I've readen your advert and maybe the lost of pressure ( I Can't be perfectly sure, as I can't see your car ) is due to wastegate failure. It seems to occur very often in the early saab 9000.
take the wastgate valve from your car, and, closing one of the two big tubes, try to swallow some air. If you can swallow through, your valve is not operating properly. Change it for the performance one at eeuroparts.com or at forge if you have the money for it ( around 135 USD, as the bosch-performance one costs around 45 ). It may be that !
 

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hello,
I've readen your advert and maybe the lost of pressure ( I Can't be perfectly sure, as I can't see your car ) is due to wastegate failure. It seems to occur very often in the early saab 9000.
take the wastgate valve from your car, and, closing one of the two big tubes, try to swallow some air. If you can swallow through, your valve is not operating properly. Change it for the performance one at eeuroparts.com or at forge if you have the money for it ( around 135 USD, as the bosch-performance one costs around 45 ). It may be that !
 

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My 87 9000T has a similar problem, although mine is a manual. A while ago though, the hose leading from the turbo to the inlet manifold came apart under the filter box. This caused quite a problem, but still, after putting it all together, i still cant get into the red on the guage. then again, i can barely get it to audibly dump pressure unless i am really working it in 2nd or 3rd gear.
 

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Welcome to Saabscene, Grentarc.
I wouldn't expect the boost on an '87 2.0T to reach the red unless it's been modified. If you're getting some way into the striped area, near the red, it's probably working fine. It was only the Aero (manual transmission), and possibly the Carlssons or the equivalent sporty models overseas that boosted into the red as standard.
 

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I have the manual turbo... and ther is no striped area on the guage.. just a blue (vac) white (boost) and red areas on the guage.
the needle goes about 2/3 the way along the white area before dropping back down....

sorry, forgot to mention that i live in Australia... and that it looks to be the top of the line with leather seats and the lot (build date of november 1986)
 
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