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Author Topic: Ongoing Boost Issues  (Read 2823 times)

Offline Immortal

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Ongoing Boost Issues
« on: 07 August 2013, 23:08 »
I have been plagued with an intermittent boost issue for the last couple of months. Basically it's like a huge flat spot in my boost curve, but it's not always there. When it happens it boosts normally to around 3k, then all boost vanishes (very noticable but no fault codes) until it reaches 4k, at which point boost comes back in full & remains into the red. It seems more noticeable when under heavy load (such as accelerating uphill).

I have done everything I can think of, however it disappears for a day or two then returns.

It's had:

MAF
Throttle body clean & realign
Fuel filter
Plugs
2.0T coils (due to a separate misfire fault)
Decat (due to separate issue)
Temp sensor (Seperate fault)
Timing belt & water pump (was due)
I've also run it with fuel cleaner & injector cleaner since the issue with the fuel filter.

I'm stuck! Could be an N75 issue or possibly the fuel pump, but the intermittent nature & lack of fault codes has me completely lost!!!

A remap might cure it, but I want it running correctly before it goes in.

Any help or bright ideas would be gladly appreciated!
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Offline Nino

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Re: Ongoing Boost Issues
« Reply #1 on: 07 August 2013, 23:15 »
You checked all vac lines? DV? And be leave me u haven't done near as much as I have  :cry:
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Offline Immortal

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Re: Ongoing Boost Issues
« Reply #2 on: 07 August 2013, 23:19 »
Yup, no vacuum leaks (that I can find) & the DV is a forge 07.

I was going to do the N249 delete anyway, but not got around to it yet!

I know it's sounds strange, but if I let off the power in the flat spot I can hear the DV dump so it's not actually losing all boost
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Offline Nino

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Re: Ongoing Boost Issues
« Reply #3 on: 07 August 2013, 23:31 »
Is your DV dumping when your just cruising about 15-20 e.g not really putting power down but your foot is just sorta resting on the gas?

You could have a leaking 007p there known for leaking that's why forge remade the piston and seals.
You could have a faulty n75 but I would first bypass your n249 it will make the world of difference.
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Offline Immortal

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Re: Ongoing Boost Issues
« Reply #4 on: 07 August 2013, 23:58 »
Sadly; no it's not. Only dumps when I release the accelerator.

Ill get some 3mm hose & get the N249 out as soon as possible. But I doubt that will cure this issue (though I can hope!!!)
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Offline mcgee9t2

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Re: Ongoing Boost Issues
« Reply #5 on: 08 August 2013, 07:31 »
has it been mapped? could just be a crap map...
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Offline Immortal

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Re: Ongoing Boost Issues
« Reply #6 on: 09 August 2013, 00:14 »
Quote from: mcgee9t2 on 08 August 2013, 07:31
has it been mapped? could just be a crap map...

No mate, I've been slowly upgrading in preparation. Last few bits are going on over the next couple of weeks
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Offline Immortal

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Re: Ongoing Boost Issues
« Reply #7 on: 11 August 2013, 19:14 »
Ok, N249 delete done & Silicone TIP fitted.

The issue has improved, but it's still there.  :cry:
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Offline Nino

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Re: Ongoing Boost Issues
« Reply #8 on: 11 August 2013, 23:06 »
What DV u using?
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Offline Immortal

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Re: Ongoing Boost Issues
« Reply #9 on: 11 August 2013, 23:28 »
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