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Discussion Starter · #1 ·
You may remember my previous posts about this.
Car is carlsson, boosts to red end of staggered line, then falls back. I took it to a specialist today, who took it out for drive. He said it is definatelt slower than it should be ast top end (especially noticeable in 3rd..initial pick up is good...then reduction...i know it will show signs of a fall off in power...but he reckons too much.
I also noticed on run yesterday that on one occasion certainly, the boost fell away well into the yellow (2/3 way up - base boost?) - obviosuly i dont always watch boost gauge, but thisa is furthest i have noticed it falling
What could cause this..any ideas?
paul
 

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Originally posted by paulmanchester:
[qb]I took it to a specialist today, who took it out for drive. [/qb][/b]
Did he not give you any ideas as to what could be wrong? If not phone him up and ask him what he thinks could be the problem,I would do this and then ask the 9K people on this forum about the advise he gave you,It's got to be worth a try
 

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Discussion Starter · #3 ·
He wans't sure...said too many variables..unwilling to say without more knowledge. He advised me to find some1 with a saab computer...he had too much work on to do it for me today, and im back in mancs on monday. He said the diagnostic computer, whilst not saying exactly, will indicate the problem area(s).
Does this sound reasonable?
 

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Sounds reasonable to me. Turbo boost problems can get as complicated as you could imagine. It could be as simple as something wrong with the wastegate or as complex as an ECU problem.

Hooking your car up to the diagnostic computer could at least tell you if the boost is or isn't being reduced due to knocking, misfiring, bad DI cassette or something else along those lines that isn't mechanically apparent.

Dave
 

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Paul,

I am having similar problems with boost at the moment and have found much information on troubleshooting. Try the Turbo Team Europe site for a good self diagnosis guide and things to test on the APC/DI system. Just try one thing for me if you don't mind. My car is a 2.3t and I am being beaten by GTi's and low spec BM's like yourself. When you accelerate hard (do this in 2nd or 3rd above 2000rpm) just touch the brake pedal enough to activate the lights but not to brake the car. If your boost gauge heads for the red you have the problem I have which I am trying to solve currently. Saab do not know what this is so don't spend the money having it put on the ISAT computer as you won't get a sensible answer. I cannot trace my fault but have several avenues left to explore. It is not the DI cartridge and I am reliably informed that the APC valve goes to full boost when it fails! (please contradict me if anyone knows otherwise, I need to know how reliable my source is!) It may be a bad APC box but I have the electronics knowledge to fix that . I feel however that somewhere we have a bad earth or bad connection. I am tracking that down at present. If you want to see someone about it I would visit Richard Elliot. Sadly I am 250 miles from him otherwise I would have been up by now.
If this has confused you don't worry but beware of people throwing parts at your car it will cost you several hundred pounds and may not do anything. I was told my DI cartridge was the problem on my car as it was the original but having it replaced made no change. I was glad it was the garages test unit they tried instead of just charging me for a new one.

Cheers,

Duncan
 

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Discussion Starter · #6 ·
Duncan, thanks for the reply, I tried this before, and it didn't shoot up, it went down (base boost??)
I have had a few replies from people who have had the same problem as me, and the lambda(O2)sensor was failing:I will test this, and see.
 
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