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Old 03-05-2010, 01:32 PM   #1
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Default Fuel cut out while driving? MLV pic inside!

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The log is zoomed all the way in.

What could be the cause of that happening?
I thought it could be spark cut due to what I thought was my tired OEM leads but after finally catching the occurance during a datalog it seems that it's down to fuel cutting completely for a fraction of a second?
This only happens when in boost, never in vacuum and it seems to always occur when making a quick throttle change. It can't be related to AE as that wouldn't cause my injector PW's to drop to 0ms.
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Old 03-05-2010, 01:39 PM   #2
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Over boost protection? Mine always spikes 2-3psi above my target pressure for a second before settling to my mbc setting.
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Old 03-05-2010, 01:46 PM   #3
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You might have it with that one! :lol:

I've just checked my settings and overboost protection is set to 7.6psi. Could it be that even though I'm only seeing a max boost during that log of 7.11psi? I know it's quite close to the overboost threshold so it would seem plausible and to add to the fact it usually occurs if I stab the throttle and am not so progressive with the accelerator
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Old 03-05-2010, 02:16 PM   #4
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Overboost will cut in if MS sees that you are GOING to hit your protection number.

Since pressure readings aren't really stable, it can appear to your controller manifold pressure is increasing much more rapidly than any real turbo could do, and will trip your protection.

This is why you set it a few psi over you target boost, or whatever your wastegate/mbc is set to.
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Old 03-06-2010, 06:24 AM   #5
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I thought so, cheers for confirming that. I've now set it to 10psi as I usually hit around 7.25psi of boost. The boost comes on extremely quick and at low rpm as Im using an mp62 charger. The overboost protection isn't really required for me in that respect. It would have proved handy in my old mk1 turbo which liked to pop actuators though

Cheers guys,
Craig
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Old 03-06-2010, 08:56 AM   #6
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Just been for a quick spin and it was overboost protection that was my problem.
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Old 03-06-2010, 09:05 AM   #7
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Quote:
Originally Posted by CRAIGO View Post
Just been for a quick spin and it was overboost protection that was my problem.
Awesome man...good to hear.

Mine was initially set at 1.5psi. I couldn't figure out why I kept hitting a wall going into boost...
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