MK5 Golf GTI
All Things Mk5 => Mk5 General Area => Topic started by: GLIDN on July 20, 2010, 12:18:28 pm
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Possible MK5 GTI Problem?
Car is 100% stock bar the new DV. Seems faster with older DV. Nothing was wrong with old DV. Just did it as I would like to go Stage 1 + Downpipe and maybe front mount + intake.
So I installed my Forge DV about 2 weeks ago.
I have not driven the car till yesterday. Girlfriend took off with the GTI.
It just seems pretty flat. No real punch.
I'm guessing I should do some logging with VCDS/Vagcom?
Now what is the factory specs of mbar pressure for the GTI?
I know it's around 12ish PSI. But cannot remember the factory spec or the conversion formula.
Now mind you I have been driving the Girlfriends mk4 GTI, Mapped and DP and DV etc. Making 130kw@the front wheels.
Now I'm not sure what kind of power I should be getting factory with my GTI.
But it seems slow and I'm thinking it could be my Brand New Forge DV.
Any help or suggestions to start looking at or considering would be truely appreciated.
Thanks
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unplug the MAF and take it for a drive
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if the problem has only just started since fitting the DV, that would be my first port of call checking its fitted correctly.
or maybe logging then replacing OE back to cross check boost levels.
Id run OE new version valve myself rather than Forge but thats my opinion.
12 pounds per square inch = 827.370875 millibars
(http://www.google.co.uk/search?source=ig&hl=en&rlz=&q=12psi+in+mbar&btnG=Google+Search)
when logging the value you expect would be 827+atmospheric pressure on the day (around 1000mbar)
so boost would be 1827 mbar :happy2:
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thanks guys will give that a go.
I only drove the car for a day after getting it and once when I replaced the valve. so not sure if there are problems but will check hopefully this weekend.
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Well it looks like I'm going to have to do some logging.
But not sure where I should start. Drove the car for the past few days.
It's intermittent on it's performance. Installed OEM DV again. Still the same.
So reverted back to the Forge DV.
On a side note.
Decided I to bite the bullet and now have Installed a Downpipe on Friday night. A little under 1.5 hours from start to finish and drove out. Not problems along the way.
Like that so much Had APR install stage 2 remap.
The car died half way thru the remap stage. They tried a few things. So car became a expensive paper weight or toy car?
Gave up and left. Got home and realized I left my wallet in my car.
Got back and had one last crack. So I told them I would look at this for them. Luckly enough it turned out to be an error on their PC.
So fixed that up. And proceeded with the burn. I now have a STAGE 2 GTI. Very nice. Fully loaded ECU too.
Again still intermittent performance. Finally had a chance of taking the car out of town. Did a round trip of about 450km's.
But my fuel consumptions is pretty horrid. I had a loan DSG GTI with APR Stage 1 and the fuel usage was pretty damn good.
So Now I know there maybe a problem but where to start?
Any idea's would be great.
So problem (potential)
Fuel Usage not great.
Intermittent performance.
Still running standard everything bar the DP and Forge DV.
It had a fresh service when I bought it 4 weeks ago.
So Replace Spark plugs and Coil-packs perhaps? maybe the air-flow sensor?
Thanks
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did u ever unplug the maf?
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No not the Maf.
Will try that today. Thanks again.
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Unplug it and give it a rag at night. Should also bring the engine light up on the dash. Then after plug it in again and rag it around some more at night. Engine light will eventually go off after a few starts.
Then report back to how you feel about the performance.
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So let me get this right, you have a car with a running fault so you got it remapped?? :confused:
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Should have fixed the intermitent problem before modifying it!
did you check boost pressure?
AFM/Boost pressure would be first port of call for me, did the tuner comment on AFR at al BEFORE remapl?? rich/lean??
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So let me get this right, you have a car with a running fault so you got it remapped?? :confused:
Kill or cure. :laugh:
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Yeah I know I should have fixed the car first.
But seeing I can turn it off and on at free will.
That was the only reason.
Never had this kind of problem in any of my mk4 1.8t's.
Will report back tonight.
In addition, it has been mapped. It's not running mapped.
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Ok ran the car without the Maf unplugged.
ESP turned off and ESP light on,'on the dash.
Ok car sill quickish but no wheel spin 2nd gear at all.
Plugged Maf back in. Wheel spin 1st and 2nd. Way more power that way.
Maybe I'm not use to the power band on a 2.0T?
Will do some maf and boost logging when I get a chance to see if there indeed is a problem.
Otherwise any other idea's I can look at.
Anyone know if the carbon canister can cause this?
As the only recurring fault I get with vag-com is carbon canister incorrect flow.
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i think your best just taking it to somebody who knows what there doing!
Who mapped it? did the tuner not make sure the car was running perfectly before putting the map on? :stupid:
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well, its going to be really hard for us to help if you keep moving the goalposts :signLOL:
The rule of thumb is to not change things any more or even revert to stock when you get a problem.
You need to get the fault codes read, look them up on
http://wiki.ross-tech.com/wiki/index.php/Main_Page
from there do some logging.
Have a look at here also
http://www.golfmkv.com/forums/showthread.php?t=24952
poor MPG may point to a failed PCV valve, which isnt uncommon in the GTI
Suggest you switch the APR map to stock mode (program 1 usually) while you are investigating the issues.
Your car should be running well and pulling stock boost, only when its doing it in 'stock mode' should you switch to mapped mode.
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Car is currently in stock mode.
As stated above.
Now the car is less than 4 weeks old.
If the pcv has failed. I'm guessing head would need to come off and be cleaned out ?
It's only downpipe and forge dv that are non stock.
I'm running APR.
Will hopefully do some data logging on the weekend.
Anyone else have comparison's I can check against?
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Id be checking the Forge DV personally. The Pcv doesnt require the head to be removed, just litterlly 4 screws once the airbox is removed. Very simple.
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Well I'll be reverting back to stock dv once my new one arrives.
Just as a precaution.
The car was checked by Apr. No error code other than the carbon canister incorrect flow. They drove the car too.
Stated it was the gruntiest stock gti they have driven.
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any idea on dyno numbers rather than just 'feel'?
on the one hand you say its 'flat with no go' and yet APR dealer says 'gruntiest stock gti they have driven'. one of you has to be wrong.
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Hence my statement a few posts ago.
Maybe I'm just not use to the power curve of the car?
I have had a Tdi mk5 gt. And audi a4 1.9tdi.
And a few mk4 gti's.
In addition if there was a fault I can fix it no problem.
I currently onl have limited experience specifically the mk5 motor.
Other than helping two guying installing stage 3 plus on their cars.
Also a few mod upgrades on Mazda mps.
Just asking generally. I have never trusted the stealerships here.
Have seen them lie to customers all to much.
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Thought I may as well update this too.
Finally got to the bottom of this one.
The problem was the brake booster. It was leaking air.
I kept hearing rushing air, till I applied brakes. VW in NZ said that is normal no matter how much I complained.
Well they have finally given in. New brake booster is on it's way. Should be here in another 10 days.
Car is driving fine the Dyno proved that.
But should see hopefully a little more boost. Maybe 1-3 psi and in addition much better fuel consumption.
Thanks for everyones help with this one.
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Brake booster? What on earth is that?
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BLIMY! just read this post all the way through an me ed is spinninggg im off for a lie down!!!!
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Yeah sorry guys,
Just trying to inform as much as possible in case anyone else ever experience things like.
Basically car power pattern was not consistent.
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Brake booster? What on earth is that?
AKA brake servo.
Uses a vacuum to assist the pressure supplied by the brake pedal on the brake master cylinder.
Comprendo? :wink:
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Your issue sounds very similar to my issue, check the diverter valve on the turbo & you'll clearly see if the rubber has a split. VAG COM doesn't pick up this fault. VW have uprated this & I'll dig out the Part nos..
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Divertor Value Part no. 06H 145 710 D
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Your issue sounds very similar to my issue, check the diverter valve on the turbo & you'll clearly see if the rubber has a split. VAG COM doesn't pick up this fault. VW have uprated this & I'll dig out the Part nos..
Thanks for the heads up. I have already tried 3 dv's 1st gen oem, forge dv, piston type oem too.
But the fact that I kept having a hissing sound till I actually drove a few gti's and noticed it was not normal after driving in mine again. Lol