Limp mode

[nikstar]

Hope someone can help,

Right its an ibiza 1.9tdi (130) been remapped by local tuning company. When giving the car some beans it goes into limp mode but does not put engine manegment light on, so no codes recorded?

Any one got any ideas?

 

[andypandypoos]

just because the engine light doesn't come on doesn't mean there's no error codes logged. if you did a scan with vag-com you'd probably find something along the lines of

17965 - Charge Pressure Control: Positive Deviation
P1557 - 35-10 - - - Intermittent

what causes this I don't really know, but it's been suggested to me that a sticky VNT mechanism could be likely

 

[ultrasound]

my pd100 used to do this after i had it remapped.. it happened whenever you reached the top of the revs in 5th gear..

the error code was saying overboost (if i remember rightly it was the code posted by andy above) which was obviously caused by the standard hoses collapsing (or opening up) at the high boost levels..

i fitted a new performance silicon hose between the hard plastic pipe and the EGR valve (90 degree bend) and it doesnt do it now.. happy days!

 

[nikstar]

There wernt any codes last time i check but it done it last nite so al put vag com when av got 5 mins!!

 

[nikstar]

just because the engine light doesn't come on doesn't mean there's no error codes logged. if you did a scan with vag-com you'd probably find something along the lines of

17965 - Charge Pressure Control: Positive Deviation
P1557 - 35-10 - - - Intermittent

what causes this I don't really know, but it's been suggested to me that a sticky VNT mechanism could be likely

Yeah thats what the code is, well top one at least. but car only started doing it after the remap??

 

[ultrasound]

positive deviation of pressure means the ECU is detecting an overboost.. dont worry as i said this isnt because the map has too much boost for the ECU to like, but that the map has too much boost for the standard hoses and they collapse at peak boost..

 

[MrNorma]

positive deviation of pressure means the ECU is detecting an overboost.. dont worry as i said this isnt because the map has too much boost for the ECU to like, but that the map has too much boost for the standard hoses and they collapse at peak boost..

I recently had a remap and this also happens to me, strange thing is i turn engine off and on again and i get full boost then. If i turn the engine off and leave it for a while the low boost problem sometimes comes back.

So i take it the best thing to do is upgrade standard hoses?

 

[ultrasound]

Yeh that worked for me.

Didn't need to do all the hoses, I just changed the final 90degree bend where it connects to the egr. Although I suppose it will depends which is ur weakest hose.

 

[rocky2008]

what causes this I don't really know, but it's been suggested to me that a sticky VNT mechanism could be likely

what is a VNT mechanish please?

 

[andypandypoos]

How Does Variable Turbine Geometry Work

 

[rocky2008]

How Does Variable Turbine Geometry Work

im lost? lol

 

[sssstew]

That link explains it perfectly with pictures so not sure how else to help you with that.

Andy refers to sticky vanes which is common, have a look back in the tdi section for loads of info.

 

[Neil82]

Yeh that worked for me.

Didn't need to do all the hoses, I just changed the final 90degree bend where it connects to the egr. Although I suppose it will depends which is ur weakest hose.

Where did you get the pipe from? Did you just fit another standard one?

Cheers
Neil

 

[muddyboots]

....the map has too much boost for the standard hoses and they collapse at peak boost..

Hoses don't collapse when they're pressurised inside...
...and if they let go or leaked under pressure, you'd lose boost and get a negative deviation error, not a positive one.

I'd say the probable causes are either turbo related (eg sticky VNT) or remap related (too much boost at high RPM).

 

[ultrasound]

it solved the problem for me, and that was the error I was getting on VAGCOM everytime it happened..

Im not sure if the hose was expanding too far and letting extra air in, or collapsing thus reducing the bore and creating more pressure in the turbo..

I got my new 90degree hose from 'Demon Motorsport' - its an ebay store but im not allowed to post links on SCN yet...

 

[chispadete]

or intake temps got to hot for boost requested meaning top speed is goes into limp mode. a better intercooler can help on a generi map this shouldnt happen however

 

[cupratdianth]

so it worth just upgrading all the standard hoses anyway? and if so wheres the best place to get them for tdi?