Hi all,

In a quest to find my surge/hesitation problem i did a n75 check with Block 118

The results are here ImageShack - Hosting :: block118ew5.png

They look quite low to me after the inital thrust what do you all think?

It's not really the full picture Martin. Try unsing advanced measuring blocks and log a couple more things.

If it were me I'd like to see Boost requested vs Boost actual alongside N75 duty and with engine speed and throttle position for referance.

Here is one that I have done -

I had a go stu but it doesn't look right.

I have done blocks 115 (boost) and 118 (N75) separately but cannot log em.

Even from this you can tell how spiky it is.Forth and fifth gear is even worse:mad:.

C__Program Files_VAG-COM_Logs_log 115.pdf

I don't profess to be an expert on this but here are my thoughts.

The first spike looks perfectly normal, i find that actual always overshoots requested when you bury the throttle and you can see it does on mine too.

The remaining peaks and troughs look like the N75 is chasing the requested quite tightly. What DV do you have in, have you got the correct spring in it or is it lifting and 'bouncing'?

It still looks to me like you aren't using Advanced Measuring Blocks -

Ross-Tech: VAG-COM Tour: Advanced Measuring Blocks

If you have this function I find it a better way to log the things I want to see instead of just using the blocks.

As Stu says advancd measuring blocks are the way to go.

If you are using Excel then I found the best way was to select the data I wanted to graph and then set RPM as the x-axis values.

Thanks chaps Its a forge dv with green spring in.

I think i may have a leak on the inlet pipe which could explain the hesitation as less air going past the maf means less fuel put through the injectors.

I will have a look at the advanced measuring blocks and try make a run but my lappy battery is about knackered.

Is the split before or after the MAF? If it's after then it'll for sure cause problems as it's allowing un metered air into the system.

After the maf. There is not a split as such, just a film of oil running down the pipe where they join.I know when they replaced the turbo there was no note of a part number for replacing the seal which joins them up.

Would or could this be the prob as it only hesitates when the turbo is at most strain?

Any air entering after the MAF is unmetered as I said so the ECU won't be including it in the fueling calculations etc.

You would think there would be some error codes popping up though if there is actually a leak before the turbo.

Thanks chaps:thumbup:

I was going to do this tonight but I don't have "advanced measuring blocks" I just have "future" something or another in the button that it's meant to be in.

I was going to test the difference in boost with the green and yellow spring and see the difference and also check my n75.

I was going to do this tonight but I don't have "advanced measuring blocks" I just have "future" something or another in the button that it's meant to be in.

I was going to test the difference in boost with the green and yellow spring and see the difference and also check my n75.

Are you on a cheapo cable?

Got it from a friend, but yea it's not an official cable.

That'll be it then

I'll log separately (well 3 at a time)!

Hope you don't mind me posting in your thread mate, did a quick run but someone pulled out right in front of me so I had to slam the brakes on... then the laptop battery died :thumbdwn:

Anyone this is what I got, about 6 lines of booting it most of the way down. I didnt boot it till about 3k in 3rd gear....

http://www.aoyt95.dsl.pipex.com/115118.JPG

The more the merrier.

You need more logs Ethos.

Armed with a better run in 3rd.

1400rpm full throttle till 6k.

http://www.aoyt95.dsl.pipex.com/3rdgearrun.JPG