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Model specific boards => Golf mk4 => Topic started by: Immortal on 07 August 2013, 23:08

Title: Ongoing Boost Issues
Post by: Immortal 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!
Title: Re: Ongoing Boost Issues
Post by: Nino 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:
Title: Re: Ongoing Boost Issues
Post by: Immortal 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
Title: Re: Ongoing Boost Issues
Post by: Nino 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.
Title: Re: Ongoing Boost Issues
Post by: Immortal 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!!!)
Title: Re: Ongoing Boost Issues
Post by: mcgee9t2 on 08 August 2013, 07:31
has it been mapped? could just be a crap map...
Title: Re: Ongoing Boost Issues
Post by: Immortal on 09 August 2013, 00:14
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
Title: Re: Ongoing Boost Issues
Post by: Immortal on 11 August 2013, 19:14
Ok, N249 delete done & Silicone TIP fitted.

The issue has improved, but it's still there.  :cry:
Title: Re: Ongoing Boost Issues
Post by: Nino on 11 August 2013, 23:06
What DV u using?
Title: Re: Ongoing Boost Issues
Post by: Immortal on 11 August 2013, 23:28
What DV u using?

Forge 007
Title: Re: Ongoing Boost Issues
Post by: Nino on 12 August 2013, 07:07
Have you have the upgraded piston installed?
Title: Re: Ongoing Boost Issues
Post by: Immortal on 12 August 2013, 17:47
Have you have the upgraded piston installed?

Err no, I haven't. When did it come out?
Title: Re: Ongoing Boost Issues
Post by: Nino on 12 August 2013, 18:39
Ring forge ask to buy a service kit really cheap comes with the new piston, most of the time if you tell them you want one because your 007 is leaking they send it for free :)
Title: Re: Ongoing Boost Issues
Post by: james2 on 12 August 2013, 19:34
I would just get it mapped , you will need the yellow spring for your dv. With out a map the car goes like :sick: with a map  :evil:  R tech is good they can come to you and bring the yellow spring for your forge 007 . They let you test drive it after and you can say what wrong ie it ticks over strange when you pull up for a sec and they clean the throttle body out and fitted my forge 007 i got off them as well   :smiley: . Well using my carb cleaner and cloth.
Title: Re: Ongoing Boost Issues
Post by: sharki786 on 12 August 2013, 22:36
Ring forge ask to buy a service kit really cheap comes with the new piston, most of the time if you tell them you want one because your 007 is leaking they send it for free :)

What if they ask "how is it leaking?" Or "could you send us pics" :wink:
Title: Re: Ongoing Boost Issues
Post by: Nino on 13 August 2013, 07:24
Just tell them you have not got the revised piston
Title: Re: Ongoing Boost Issues
Post by: sharki786 on 13 August 2013, 07:34
Just tell them you have not got the revised piston

Nice :cool: