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Model specific boards => Golf mk6 => Topic started by: RocketRossUK on 27 August 2013, 09:07

Title: Fixing a Flat Spot in the Rev Range
Post by: RocketRossUK on 27 August 2013, 09:07
Hey guys,

Just a quicky, just the other day i felt a big flat spot in 3rd while accelerating. It has been fine up till this point so i can rule the map out. It doesn't seem to happen all the time. Really need to take it on a full run with loads of 3rd and 4th gear pulls

Main thing i would check is DV, Coils, Plugs. Just dont which order is best to try. Obviously i should check Dv first, but my jack is broke at the minute, so cant just whip it up and check.

Has anyone else had a flat spot and changed any of the above with good results.

 
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: barrym381 on 27 August 2013, 10:10
a jack to get to your dv  :undecided:
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: Poached on 27 August 2013, 10:19
Going to need VCDS or a logging session really as this could be a number of things.

What RPM is the flat spot?
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: Rhyso on 27 August 2013, 10:38
a jack to get to your dv  :undecided:

Its a MK6; its fitted at the back of the engine and underneath
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: Marshy on 27 August 2013, 10:49
Ross I know you say its not the map but have you tried putting it back to standard to check?
Your bluefin aren't you? If so a quick easy check.
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: RocketRossUK on 27 August 2013, 11:10
Ross I know you say its not the map but have you tried putting it back to standard to check?
Your bluefin aren't you? If so a quick easy check.

Its not map, it been pulling hard and fast for 2 months, wouldn't just change.

Its around 3000 revs. Im thinking it gonna be a teared DV, I remember when it happened on my MK5, think it did the same.

I have VCDs, what menu do you use to test boost / flatspots?
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: Rhyso on 27 August 2013, 11:19
Engine module

Think boost is block 110 / 115

Or they start at block 10
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: RocketRossUK on 27 August 2013, 11:34
Engine module

Think boost is block 110 / 115

Or they start at block 10

Thanks for the reply. Then what do you do with it? does it show you fault or lack off boost etc...
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: Poached on 27 August 2013, 12:23
Firstly see if you have any faults stored in the ecu memory.

Then you could measure boost pressure requested vs actual boost pressure produced with N75% (Wastegate).

There are many variables you can measure in VCDS. You are probably best exporting the data to excel and producing a graph to see what's happening or taking it to a tuner with a dyno to test in a controlled environment.
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: Rhyso on 27 August 2013, 12:46
As per Poache's reply  :smiley:

It will give you specified VS actual values so you will see if you are losing boost  :nerd:
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: RocketRossUK on 27 August 2013, 14:37
As per Poache's reply  :smiley:

It will give you specified VS actual values so you will see if you are losing boost  :nerd:

Wish you were closer to me  :sad:

What sections in VCDs can i use to measure / check if boost and air is correct. Do you have a guide or instruction i could follow
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: Rhyso on 27 August 2013, 16:13
Quote from: RocketRossUK link=topic=258641 .msg2374670#msg2374670 date=1377610630
As per Poache's reply  :smiley:

It will give you specified VS actual values so you will see if you are losing boost  :nerd:

Wish you were closer to me  :sad:

What sections in VCDs can i use to measure / check if boost and air is correct. Do you have a guide or instruction i could follow

Posted them earlier  :wink:

Go into Engine then measuring blocks and scroll through  :smiley:
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: RocketRossUK on 27 August 2013, 19:47
Quote from: RocketRossUK link=topic=258641 .msg2374670#msg2374670 date=1377610630
As per Poache's reply  :smiley:

It will give you specified VS actual values so you will see if you are losing boost  :nerd:

Wish you were closer to me  :sad:

What sections in VCDs can i use to measure / check if boost and air is correct. Do you have a guide or instruction i could follow

Posted them earlier  :wink:

Go into Engine then measuring blocks and scroll through  :smiley:

And do what with the values?...what should they be?
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: jhunter_83 on 27 August 2013, 20:18
Mine does the same, I have checked and no faults stored.

I am 99% that its the bluefin map
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: Rhyso on 27 August 2013, 20:22
The measuring blocks give you specified (what the ECU requests) vs ACTUAL which is what the car produces

The numbers need to match. Do a full throttle run in 3rd gear to the redline. In the lower rpms the numbers wont match as the turbo spools up but once the turbo is spooled then the numbers will follow each other to the red line. If the actual tails off vs the specified then you got a problem

DV generally doesnt flag as a fault unless its kaput
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: RocketRossUK on 28 August 2013, 08:48
Well i have bought a New Rev G DV, Should get it fitted this weekend.

But im starting to think it may be caused my Spark Plugs or Coils. Hard to explain how it feels, just doesnt feel strong as normal, like its not pulling hard.
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: Poached on 28 August 2013, 09:57
Well VCDS can be used to detect a misfire if it isn't stored in the fault memory already.

http://wiki.ross-tech.com/wiki/index.php/Category:Fault_Codes

Have you checked for any stored faults yet?
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: RocketRossUK on 28 August 2013, 10:30
Well VCDS can be used to detect a misfire if it isn't stored in the fault memory already.

http://wiki.ross-tech.com/wiki/index.php/Category:Fault_Codes

Have you checked for any stored faults yet?

Yeah no fault codes in regards to engine when doing a general scan. Just a mirror fault - which i know about, and a SatNav one which i know about.

Do you have to do a certain scan in a certain section?

Title: Re: Fixing a Flat Spot in the Rev Range
Post by: Poached on 28 August 2013, 10:51
Not for an auto scan.

Did you ever have a dyno run when the map was put on?

I recommend a dyno run to log some key blocks to determine if there is a problem.
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: RocketRossUK on 28 August 2013, 11:02
Not for an auto scan.

Did you ever have a dyno run when the map was put on?

I recommend a dyno run to log some key blocks to determine if there is a problem.

No Dyno as it was Bluefin. The problem has just arrived in the last few days. Its been running sweet for 2 months.

There is no real decent tuner with a RR near me, nearest one is Awesome or Stallers and they have a 2 week waiting list.

It just feels a bit hesitant through out the rev range - Im sure its gonna be the DV....if that doesnt fix it then dyno may be needed.
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: RocketRossUK on 28 August 2013, 21:38
Ok, so i went out and did a few pulls tonight. Its so strange it only hesitates every other pull, usually in 2nd or 3rd around the 2500-3000k.

It holds for a second then goes. the revs dont go up so can be clutch slipping....just hope its a case of ripped DV (fingers crossed)

Anyone had similar?

Im gonna fit the DV this weekend and see whats what. If its still there i will have to pay for some diagnostics / Rolling road   :undecided:

More freaking money i dont have
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: Marshy on 29 August 2013, 04:54
This won't be a split DV mate as they either hold boost or they don't and your not complaining about performance.
For the time it takes and no expense I'd try the car in standard tune also.
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: RocketRossUK on 29 August 2013, 08:48
This won't be a split DV mate as they either hold boost or they don't

I dont think that is true, on my MK5 i also had a DV split (hard to remember as it was a while ago)
but if it has a split it can still hold boost, just not very well.

It not on or off if it has a small tear / split. I may put standard tune on for a while, but dont want to keep flashing ECU as it will show on the counter.
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: jhunter_83 on 29 August 2013, 12:56
Why are you bothered about the counter? Have you a warranty on it?

If vw look they can easily tell the counter has increased, date and mileage of that count.

Once you mess about, your warranty is null/invalid. Speaking from personal experience :)
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: RocketRossUK on 29 August 2013, 16:11
Ok, so i removed the map went for a half hour drive and it seemed fine..... :huh:

So reload map and it also seems fine, i could do with giving it a full hour drive out, but how can reloading change it so much

There seems to be no problem with the MAF sensor....make no sense. Anyone?
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: Marshy on 29 August 2013, 16:40
Mmm does this sound similar to someone else's problems????
Once the maps reloaded it will probably need to readapt so will probably return in time.
Everyone thought I was taking the pi$$ when I said about mine.
Especially the fan boys on the mk5 forum who don't even run the software in question.
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: RocketRossUK on 29 August 2013, 17:24
Mmm does this sound similar to someone else's problems????
Once the maps reloaded it will probably need to readapt so will probably return in time.
Everyone thought I was taking the pi$$ when I said about mine.
Especially the fan boys on the mk5 forum who don't even run the software in question.

I know what your saying, but i dont think its the same problem  :undecided:. Mine wasnt gradual, it was fine one day and not the next, i didnt have any knocking, just a small hesitation.

Plus it doesnt take 2 months to adapt which ive had the map for, and i have had the Carbonio in for 2+ weeks.

Engine only usually take 100-200 to fully adjust. Strange as hell
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: Marshy on 29 August 2013, 18:57
When I say sounds familiar I meant more in the time scale not the problem.
Yeah it'll be interesting to see if the problem returns after its done 50-100 miles.
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: Neil gti on 31 August 2013, 07:04


Sorry to here you've got a gremlin somewhere 
The only time I experienced anything like that was when I had my Revo stage 1 map put on, I had the same symptoms as you and was very annoying, that was when Revo had just released it and was about 3 years ago now, It took them a few months to bring an update out for it, but when they did it totally cleared the flat spot,

When my DV's have failed in the past it didn't feel like that it just felt underpowered  and a bit like a Normally aspirated car,
Title: Re: Fixing a Flat Spot in the Rev Range
Post by: GolfTi on 31 August 2013, 23:55
It's the bluefin map.

I used to change back to stock quite a lot and noticed this after a little while with the bluefin.
Never with stock but only with bluefin after a few runs. Didn't bother looking into it any further as I knew I was trading in soon.