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Discussion Starter · #1 ·
Sorry if this is a bit long but this has been happening on and off for the past few weeks. When im driving on the highway trying to maintain a speed, my car stutters slightly. It doesnt seem like a misfire. If i hold my foot on the gas pedal steady and keep the needle in the green on the stock turbo gauge, the car will accelerate a little bit and then bog down and accelerate a little again, it fluctuates. When this happens the needle on the stock turbo gauge fluctuates as well. The car accelerates smoothly and steadily, its still pretty quick and it idles fine. But overall throttle response isnt as sharp as it was.

current milage is 133,400.

the throttle body was replaced at 84,500 - so 48,900 on it
MAF at 87,300 - 46,100 on it
nordic stg 3 tune at 89,800
new di casette at 89,800 - 43,600 on it
crank positioning sensor at 91,600 - 41,800 on it

i cleaned the throttle body, it wasnt really dirty but that didnt help
checked my vacuum lines they all seemed fine
i also cleaned the MAF with MAF spray, and new air filter, that didnt help
i changed the spark plugs with the correct NGKs, that didnt help either

Can this be fuel delivery related or maybe the cps? or maybe even maf since the stock turbo gauge fluctuates. but i feel like the maf or throttle body shouldnt fail yet.
 

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My cousin said his new to him 107k '00 Aero has the boost gauge kind of flutter up when driving steady on the highway. Sounds like the same symptom you are experiencing. I need to drive the car and see.

I am going to start with throwing some new plugs in and see what happens next.
 

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Discussion Starter · #3 ·
Yea that does sound very similar. Spark plugs are worth a shot but didnt do me any good. It seems to start once the car is at its normal operating temperature, isnt that a cps symptom?
 

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Yea that does sound very similar. Spark plugs are worth a shot but didnt do me any good. It seems to start once the car is at its normal operating temperature, isnt that a cps symptom?
I never had a bad CPS, so I have no experience with the symptoms lol.
 

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Discussion Starter · #5 ·
Me neither, I just remember reading that somewhere. I replaced it more as preventative maintenance, and it did run slightly better after i changed it.
 

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thats exactly the symptoms i had when the TB took a shit. but it could also be a cps issue. i wound up replacing the CPS only to find it was the TB.

dod you get a new or rebuilt/used TB?
 

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Hmm.. you sure it isnt a misfire? That is what it sounds like to men, but I wouldnt know unless I was in car. You got a new dic and new spark plugs so I am not too sure where to go from there, you seemed to have covered you basis with the vacuum lines and such. Does it only occur under boost? or does it occur in vacuum as well?
 

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My ng900 has been doing this crap too, except mine has shut off. I'm changing the fuel pump tomorrow to see if this does anything.
 

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Discussion Starter · #9 ·
thats exactly the symptoms i had when the TB took a shit. but it could also be a cps issue. i wound up replacing the CPS only to find it was the TB.

dod you get a new or rebuilt/used TB?
Yea it seems to be between these few components.

I bought a new tb from the saab dealer about 3 years ago.

What actually goes bad on these throttle bodies? I have the original one that went still, I took it apart real fast and it seems pretty straight forward, two coils and a rotor controlling the valve.

Hmm.. you sure it isnt a misfire? That is what it sounds like to men, but I wouldnt know unless I was in car. You got a new dic and new spark plugs so I am not too sure where to go from there, you seemed to have covered you basis with the vacuum lines and such. Does it only occur under boost? or does it occur in vacuum as well?
It doesnt feel like a misfire. It feels more like an electrical/sensor issue.
It never occurs under boost only in vacuum according to the factory gauge.

My ng900 has been doing this crap too, except mine has shut off. I'm changing the fuel pump tomorrow to see if this does anything.
Let me know if that makes a difference.
 

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Discussion Starter · #10 · (Edited)
So I found this thread:

http://www.saabcentral.com/forums/showthread.php?t=102352&page=11

It sounds like its the throttle body. I cant believe there are tb issues again already. I'm going to see how it pans out in the next few days and if its annoying enough or gets worse try taking it apart and cleaning it. If that doesnt work i'll order a re manufactured one with a lifetime warranty. There is no way I'm spending another 480 on a part thats just going to break again.
 

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Discussion Starter · #11 ·
Update: I took apart the throttle body and sprayed the potentiometer with MAF cleaner the other day and so far so good. I also did the bpv solenoid bypass. Throttle response feels much better now, and so far no issues trying to maintain a steady throttle.
 
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