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Old 10-24-2007, 04:10 PM   #1
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Default high rpm/boost issue?

I have searched and found nothing.
not really sure where to post this... since this isn't a Greddy or DIY.

As usual my car revs and idles perfectly normal, first gear at WOT has no issues until about 6000 RPM then comes the problem.
my car will bog like it is starving for air, in second the same problem comes only sooner, at about 5000 RPM and it comes progressively sooner the higher gear you are in, on the freeway in 5th it happens anytime you go half throttle or more. It isnt as bad if you stay out of boost and speed up slowly but it will still happen at about 6K in any gear. At first the A/F ratio would go nutso rich down to 11:1 sometimes 10:1. I adjusted it back to 12:1 with the voodoo box, but it still happens.

Boost is set to about 5.5 PSI

Retarded the timing to 6 degrees
The turbo makes a funny noise when it happens... it makes it's spooling sound but it sounds like it intermittent. for example if the line were the spooling noise
Normal:
------------------------------------
Problem:
------------ ------- -------- ------ - - - - - -
Like it is cutting out...

thatís probably a shitty way to describe it...

Could it be a boost leak??

I'd ask FM but they usually take 3 days to reply..
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Old 10-24-2007, 04:12 PM   #2
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clutch
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Old 10-24-2007, 04:13 PM   #3
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Call FM, emailing is pointless if you want an answer.
You might have leak at your BOV, what kind is it and is it recirced or VTA. Otherwise bogging is usually a symptom of going lean. You do have a wideband right?
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Old 10-24-2007, 04:14 PM   #4
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Quote:
Originally Posted by Ben View Post
clutch
lol I forget about that one, figure that would be pretty apparent to most people.
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Old 10-24-2007, 04:20 PM   #5
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It isnt the clutch slipping..
it a GFB blow off valve, recirculated, not leaking.
it doesnt go lean at all.
and I do have a wideband
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Old 10-24-2007, 04:25 PM   #6
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Try putting in new plugs.
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Old 10-24-2007, 05:39 PM   #7
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if it were the clutch slipping wouldnt it slip and keep slipping?? not slip then grab then slip... etc.. ??
the plugs are almost brand new.. I changed them about a week before I put the turbo in, so less than trhee months ago. they are NGK iridium IX
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Old 10-24-2007, 10:36 PM   #8
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It is a cheap check to swap them out. Also check the coil grounds.
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Old 10-24-2007, 10:56 PM   #9
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what are they gapped at?
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Old 10-24-2007, 11:14 PM   #10
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Sounds exactly like what I would have described when my clutch was giving out. its worse in higher gears because there is more load. Progressive throttle doesn't make it slip because there is no tq burst but its gonna let out eventually because it can't hold the tq.
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Old 10-24-2007, 11:15 PM   #11
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Quote:
Originally Posted by nicacus View Post
if it were the clutch slipping wouldnt it slip and keep slipping?? not slip then grab then slip... etc.. ??
the plugs are almost brand new.. I changed them about a week before I put the turbo in, so less than trhee months ago. they are NGK iridium IX
Boost is dependent on load. Slippy cluch = less load = less boost = clutch cools and grabs = more boost = clutch slips

break up with load usually indicates ignition grief, typically plugs or wires, but your description sounds more like clutch to me.
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Old 10-25-2007, 12:26 PM   #12
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If I had to take a shot in the dark at what detonation felt like I would say that’s the best way to describe what it feels like.
I have had my clutch slip before this is a totally different feeling. It isn’t a gradual not wanting to go feeling, it's a sudden hesitation like you would get if you were teaching someone how to drive a stick and they were trying to start in third gear.

I'm not sure what the plugs are gapped at.. I don’t think the gap was ever changed from when I bought them. I will pull them tonight after work and check them out.
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Old 10-26-2007, 03:57 AM   #13
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the NGKs were gapped at like 45
I bought some cheapo autolites that are for the 323 GTX and gapped them at 35
problem solved...

again I feel like an ***..

Thanks for the advice
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Old 10-26-2007, 08:26 AM   #14
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Switch to COPs and you can run .40 gap.
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Old 10-26-2007, 09:35 AM   #15
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Quote:
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what are they gapped at?

what a smart post!
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