On a 1.8T Mk1 Octavia I am getting the 17705 at idle, if i clear it while the engine is idling it comes straight back? is this more likely a sensor fault than a boost leak? I have replaced DV with Forge007, I have replaced the turbo to pancke pipe with the revised one and i have replaced the "Suction Jet Pump" and when the car is not in limp mode it goes really well. I have tried pressure testing the pipework but cant find any leaks. on a block 32 I am getting -0.4% and -3.6% which I believe are good readings. I am at a loss where to go next, N249 bypass or N75?

Throttle body, clean out and re adapt.

I Bought a spare gasket the other day as I was wondering if the increase in boost might have picked up some crap from the I/C. the throttle body was cleaned a few months ago but cant hurt to do it again I suppose just have to wait for this weather to blow over. Another question but not sure if its related (have read so much about it that my head hurts) since the remap I get surging on WOT and when I do a block 120 it is really clear how much this is effecting the perfomance. from 1200RPM to redline in 2nd it gives 3 or 4 surges, or rather it appears that the boost drops off and then the surge is the boost building again. Is it possible my N75 is tired and I need to replace with a new F one or do I need to go to a H, J or K even?

Does it give one big surge early in the rev range followed by smaller surges or are they all equal?

Also is the surging happening when the 17705 is present?

when you WOT it spools up as expected(lovely feeling) but then its like the boost has dropped(havent fitted boost gauge yet - its on the list of things to do)and it needs to build again does this three or four times on the way to the redline they feel equal. The 17705 is always there? so I dont think its that causing it. Is it the N75 trying to keep the engine from overboosting? or is it not up to the job?

I did have a Boost leak from the turbo to pancake pipe, but the new one is nice and oil free and if I do a block 115 uphill in 3rd or 4th the boost seems to hold at the correct level. I think my Vac is good now as well (due to the block 32 readings) I do sometimes get the part throttle judder/stumbling (not like a missfire - more like it cant make up its mind what its supposed to be doing!) which is why I was considering the n249 bypass - is this worth doing Lummox?

What site do you guys use to host pictures? as I have the logs that I can put up.

What site do you guys use to host pictures? as I have the logs that I can put up.

Photo bucket is ok

Ok Photobucket it is then.

This is the block 120 which shows the surging/boost dropping

this is a portion of a block 115/118 run this was done uphill in 3rd 4th to make sure boost would be required for a while. as you can see it has breaks in communication which on the second bit when it come back, limp mode is active due to the 5.1 % duty cycle.

if you look at the time stamp there are two bits where it drops out

It looks like it's spooling too quick at the start with the 100% duty cycle which will cause the boost to bounce when moving. I once had a map which gave 95.3% duty cycle and it bounced a bit at the beginning. Current map hits about 75% max.

I would tell Ecu Evolution ( DNA) about this and see what they say. Your map was made for a gas version so maybe it is different to mine and others.

Just my interpretation

This doesn't look right too me Your ecu is requesting 1990mb and getting 1210 and it's the same going up rev range.

At least I think I'm right, but don't quote me lol.

Boost leak ??????......................Still :(

Edit too add, You may already know this

should it not be 100% until it gets to the required boost and then back off till the level of boost is steady with small fluctuations to keep it in range? the run was done in a higher gear to make sure there was a good range of values, as a run in second is hitting the redline very quickly and the ebay cable I have seems to max out at 1.8 readings sec with 2 blocks (0.8 with 3 or 2.5 with just one)

apart from the boost steps how does the curve look compared to yours Martin? looks like it would be a nice smooth curve if I can sort it out.

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This doesn't look right too me Your ecu is requesting 1990mb and getting 1210 and it's the same going up rev range.

At least I think I'm right, but don't quote me lol.

Boost leak ??????......................Still :(

Edit too add, You may already know this

it was done from low revs in higher gear so took a while for the boost to build.

it was done from low revs in higher gear so took a while for the boost to build.

Doh ...................I did say don't trust me lol

Here's mine

I would advise you do a run in 3rd gear logging one block at a time and going up to 6k, this way it gives us a proper look at whats going on.

Your cable should read information quicker than that are you on 409.1 software?

I think I have read that most mappers keep the duty cycle to a max of 95%... but i maybe wrong on this.

yes the software is 409.1 but the fastest it reads is 2.5-3 on a single block? tried it on a faster laptop and no different, assume it is either the cable or the ECU itself ?

Strange mine reads every 0.4 secs on a single block and every 0.9 secs on two blocks.

Ebay cable.

I think mine is showing readings per second so 3 readings per second for one block 2 for 2 etc

OK. here is the boost vs spec. it was a third gear run but not able to take it to 6k+ but starts from 1k.

Didnt seem to surge too much either?

Also did TB clean tonight and the 17705 still comes back at Idle? was only a little bit dirty compared to the last time!

Here is my last map which caused hesitations / surging.

Looks similar to yours doesn't it?

By the look of it you are getting a big kick to start with but the n75 is pulling boost back too quick to compensate. This is causing a hesitation followed by a surge which can end up bouncing boost IMO. On some of the maps like mine it did settle down after a couple of surges.

I would contact Chris about it.

I spoke to Chris last night and he has the same map on his Octavia 1.8T Elegance estate. He has done the N249 bypass and said that it had improved it but it is still surging a bit so he is sending the file back to John at DNA for some tweaking. Once they have got it right I am going over as well.

The thing that is annoying my now is this damn 17705!!!!! As suggested By Lummox I did the TB clean and reset the TB as well, but the code still comes up, hot or cold at Idle? clear it with the engine at Idle and it pops straight back up? How can you have a pressure Drop when Atmospheric is higher than the requested at Idle anyway?

Here's mine

I would advise you do a run in 3rd gear logging one block at a time and going up to 6k, this way it gives us a proper look at whats going on.

Your cable should read information quicker than that are you on 409.1 software?

I think I have read that most mappers keep the duty cycle to a max of 95%... but i maybe wrong on this.

I like the way this holds the boost at 2000millibar all the way to 6k !!!!!! was this file from DNA as well?

Did your first map ever cause limp mode? as mine seems to drop in to it after a blast, then all OK after a restart.

Edited 11 March, 200917 yr by karlbar2k

Yeah DNA file, it requests 2000millibar but doesn't quite make it lol. I want to go to DNA direct when i have the cash to get a map tweak for the FMIC and see what she puts out then.

The 17705 is certainly a hard one to cure, I presume you had it before the remap?

I sure did... also had the N249 mechanical malfunction, but this went after fitting the Forge 007.

Like I said, its the fact that it occurs at Idle that is throwing me?

my hesitation is completley gone. map has been tweaked and drives great. pulls hard all the way through the revs every gear!!

17705 is still there but i think that is now down to the forge split r. also limp mode problem i had on start up seems to be cured. not shown up since touch wood

my hesitation is completley gone. map has been tweaked and drives great. pulls hard all the way through the revs every gear!!

17705 is still there but i think that is now down to the forge split r. also limp mode problem i had on start up seems to be cured. not shown up since touch wood

I spoke to the Master Technician at WhiteDove in Cardiff today about the 17705 at startup and at idle and the suggestions were:

1) Vac Pipe?

2) N75

3) N18 (PCV Valve?) :confused:

4) Turbo :eek:

apparently "They" have replaced lots of turbos on early ones.

Ive been to ECU Evolution today to have my map tweaked (same as Martziniuk I think) and now all I can say is WOW (no not world of warcraft) the initial pickup is smoother and it really pulls well and no more limp mode!!!!