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Discussion Starter · #1 ·
Hey guys,

A litte stumped as to why my car is bucking when it creates a lot of boost pressure. Anywhere from around 15psi and up. I have a brand new ignition cassette. I just put in brand new NGK laser platinum spark plugs. They have only been lasting me around 8,000k a set with a stage 3+ ecu upgrade. From what I know extra boost pressure results in less spark plug life. But the new spark plugs that I just put in still aren’t stopping my bucking issue. They always have in the past. I had an engine light blink at me today after it bucked hard. I am assuming from a bad misfire and then it went away. Could it be from bad fuel pressure? I have 119k on the stock fuel pump. Any other thoughts or suggestions?

Thanks,
James

Saab 9-3 2002 2.0T
Stage 3+ECU Talifero tuning
 

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I am moving your thread to the NG900/OG9-3 tech forum where you will get more response.

You have described a fuel cut like symptom, as when a stock car for some reason exceeds the ECU boost request. Check to make sure your BPC is properly connected (all three vac lines) and ensure it is functioning properly. Check the operation of your wastegate actuator as well, since if it is frozen, that can allow the overboosting too.
 

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What are your plugs gapped at? I think I gapped at .032 on a stage 3+ t7 car. Try setting your gap .002 closer and see if that fixes it. The bucking is more than likely spark plug flame-out from higher boost.
 

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Discussion Starter · #4 ·
I am gonna try to gap them closer and see if that makes a difference. I think the extra boost pressure is making the gap harder to jump. Just strange how with the last two sets I put in, the stock gap was ok. I have a 3.5 bar fuel pressure regulator that I put on with the tune. Boost gauge has vac pressure. The waste gate is ok and all three hoses are on the BPC.
 

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On my Stage 3 car anything larger than 0.035" I would get a slight stuttering/hesitation under hard acceleration/higher boost. I set them to 0.032" and never had a problem after that.
To the OP, is it a hard buck, like bang you just hit something or more subtle like you just lose a little power for split second?
 

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On my Stage 3 car anything larger than 0.035" I would get a slight stuttering/hesitation under hard acceleration/higher boost. I set them to 0.032" and never had a problem after that.
To the OP, is it a hard buck, like bang you just hit something or more subtle like you just lose a little power for split second?
Agreed! I had your exact symptoms a ways back..Try a tighter spark plug gap
 

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Change gap on the plugs...
Change plugs after every other oil change.
Clean your MAF
Check your fuel pressure at the rail
 

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Discussion Starter · #9 ·
Problem Solved

So I ended up decreasing the gap to 0.030 and the car is doing the great now. It's back to it's normal self. Finding a quality gap tool was the hardest part. And everyone talking to me about it said oh no don't decrease the gap on a platinum plug. Needless to say I chose not to listen to their advice.

Thanks guys,
James:cool:
 

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So my waste gate actuator seems to be OK I can move it by hand it does not however move by reving the engine when exactly is it suppose to move...should it move when reving the engine or is it just when the engine is underload
 

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Jimmy where about in ct are you I'm in central ct new Britain got a lot of parts for saabs... if u ever need anything let me know
 

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So my waste gate actuator seems to be OK I can move it by hand it does not however move by reving the engine when exactly is it suppose to move...should it move when reving the engine or is it just when the engine is underload
It moves when it dumps boost, revving will never do this.
 

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Try disconnecting the bpc. See if it still has the problem. If it resolves the issue then u need a new one... if it still does it and the waste gate isn't stuck then check your map and ur maf (if u have one).
 

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Discussion Starter · #16 ·
0saab0

Jimmy where about in ct are you I'm in central ct new Britain got a lot of parts for saabs... if u ever need anything let me know
I am about an hour away from Hartford. Southbury/Oxford line. Looking for a dashboard for my Saab 9-3 2002. It's a black interior. Let me know if you come across anything 0saab0.
 

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Discussion Starter · #17 ·
MAF Sensor Issues

To all of you having a possible MAF sensor issue.

Press the plus and minus on your “stock” head unit for your audio system.

Scroll till your get the to the numbers 22 & 23
It will give you the number values of:
mReq for 22
mAir for 23

This will tell you how much air your MAF sensor is requiring, and how much air your MAF sensor is actually getting.

If the number are off. Go to your local auto parts store and get MAF sensor cleaner and pull the MAF out of the car and spray it and try again.

If the problem is still not fixed, consider a new MAF sensor.

If the problem is still not fixed after the new MAF sensor....

Go to your boost control and make sure the three hoses are connected to where they are supposed to be. If thats a yes. Take the boost control off and spray some air through the 3 holes to clean them out and put it back on and try again.

CAREFUL with pulling the hose off of the waste gate that is connected to the boost control, if you do decide to diagnose the waste gate as faulty with the hose disconnected. There is NO limit on the boost that the car will generate. Causing your stock intercooler to implode if you boost too much. I speak from experience. Lets just say that Nick T from Genuine Saab sells a nice aftermarket one for around $400.
 
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