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Discussion Starter #1
When you give it the beans my boost gauge hits red then bounces until it shifts. What is it and can I change it or delete it?
 

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Discussion Starter #4
It'll hit the red and then pull power until its back in the orange and then do it again. It feels hilarious.
LOL, that's a good one.
 

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It sounds like you're hitting fuel cutoff. Do you have a manual boost controller or a bigger than stock turbo?
 

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It could also be a weak DIC, iffy fuel system, bad BPC, vacuum leak, or some other combustion characteristic that's causing it to pull power to prevent knock. What year is the car? What model? What engine?
 

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Discussion Starter #11
Well, that won't work for this model I guess. It did throw a code. p1549. It'll studder and kill the fuel for a second. Then, it won't build boost completely. I stop turn the car off then back on and it'll boost hard then do it again. Throttle position sensor?
 

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Let's talk about the bypass that you figured out.... it's likely the source of your problem. The engine management is designed to perform in a certain way with specific inputs. If you start trying to outsmart it with exciting new variables, it's more than likely to surprise you with unwanted side effects in return.
 

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What pressure are you boosting to when this happens? Are you sure that the APC vacuum hoses are connected properly? If not, you could overboost the engine and cause severe knocking. You really shouldn’t mess with high boost levels (above like 1bar) unless you are in T5 suite and make sure your AFR is good and you aren’t knocking. If tuned properly your engine will produce a lot of power, but could be dangerous otherwise.
 

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^ What they said. Either the plumbing to your boost pressure control valve is wrong; your BPCv is bad; or you have a (rare) ECU MOSFET output issue.

Get the BPCv hooked up by the book. Report the results. Then pull the W hose. Test again with some WOT and see what it does (should hit fuel cut hard). Report back.

EDIT: Do you have the WIS? There is a trouble shooting procedure in there you can also use.

272039
 

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Discussion Starter #16
I never did do that bypass. All of the hoses are still in the right place. It's either the bpc or the tps. I'll check the bpc hoses later and see if the w hose is still in functioning order. But the fuel cut is really hard but only for a split second. After that it'll boost right until it throws that code and limits boost to 75%ish.
 

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What happens if you run WOT up a highway hill with the W hose off? Hard fuel cut? It should feel like you hit a wall... and your boost gauge should hold tight in the red until it gets there. Do the test.
 

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I'm not sure what would cause a T5 car to intermittently hit fuel cut. Doesn't sound like TPS or BPC. It sounds like a mixture or maybe ignition problem to me.
 

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Discussion Starter #19
What is WOT? It does feel like I hit a wall. And it sounds like it pops when this happens. After that, it clears until I punch it and downshift again.
 

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Discussion Starter #20
I'll go take a video of what it does when I hit it and post it to the Saab owners USA page. My f book name is Everett
Marks.
 
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