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chris479
18th January, 2012, 08:00 PM
HI please could anyone advise me if it is possible to alter the ecu envelope to stop the engine going into limp mode because of turbo overboost (spiking) mostly vag diesels thanks.

z786
18th January, 2012, 09:20 PM
have u tried cleaning the vanes in the turbo??

chris479
18th January, 2012, 09:58 PM
thanks for the reply yes vnt is working ok at about 100k this is a common fault certain conditions cause overboost and limp mode turn off and back on everything ok I think someone may be able to advise on either lowering boost or allow more boost before mil is activated

Youneselm
18th January, 2012, 10:00 PM
clean the variable giometry off the turbo.
bey bey error

chris479
18th January, 2012, 10:02 PM
how do I do that

mislav88
18th January, 2012, 10:32 PM
remove turbo and clean it

VRPerformance
18th January, 2012, 10:34 PM
or change the N75 valve + check the vacuum hoses,the hoses from the turbo to the intake manifolt...etc

Youneselm
18th January, 2012, 10:48 PM
if the vacumm hoses, or N75, or intake manifold is defective or damaged, the car dont pull.
result no charge pressure in engine.
Overboost is only, generated by the geometry in turbo that blocks in the high pressure position.
TAKE OFF TURBO AND CLEAN THE VARIABLE GEOMETRY, AND JOB DONE.

z786
19th January, 2012, 12:57 AM
thats what i said, CLEAN THE VANES

VRPerformance
19th January, 2012, 04:52 PM
if the vacumm hoses, or N75, or intake manifold is defective or damaged, the car dont pull.
result no charge pressure in engine.
Overboost is only, generated by the geometry in turbo that blocks in the high pressure position.
TAKE OFF TURBO AND CLEAN THE VARIABLE GEOMETRY, AND JOB DONE.you are not right,also if the N75 valve is damaged the car will overboost!

ecutuners
19th January, 2012, 05:22 PM
Listen to z786 hes right, its the veins sticking

pablo1971
19th January, 2012, 08:15 PM
OR A UNDER PERFORMING N75 VALVE.......the n75 are cheap enough,try and replace it,check all pipes

chris479
19th January, 2012, 09:33 PM
read the post please, turbo is clean, vacuum pipes are ok, it is not n75 it is the later square black boost unit on bulkhead it is ok. as I said these systems at about 100k must wear a little and cause overboost in certain conditions, I would like to know if it is possible to alter software to keep the light out

furnata
19th January, 2012, 09:48 PM
You can set boost limiter higher i mean SVBL

paddyp
20th January, 2012, 04:15 AM
If it is just 'wear' all you have to do is adjust the actuator rod 10mm spannner open the lock nut and turn to make the rod longer .. done.

pablo1971
20th January, 2012, 08:19 AM
have you logged the car and set the actuator/maf duty cycle up......you need to log and set the actuator....if the car is a 5 speed box,you have to log the car and do a run in 4th gear,log it from 1000 rpm upto the red line,and at 4ooo rpm the maf duty needs to be around 70-80%......you adjust the actuator and it aters the duty......adjust till you get these figures.... also when you log the car,overboost accurs when the duty is too high,so if the duty is hitting 90-100% before 4000 rpm this is when overboost will happen... VNT TDI turbo: how to adjust actuator & cure boost problems - uk-mkivs (http://uk-mkivs.net/forums/t/353504.aspx)

paddyp
20th January, 2012, 12:21 PM
By the way pablo is correct a sluggish or worn boost valve will effectively increase the duty cycle and cause excessive boost.

The newest ones have a vane position sensor on the turbo too that gives problems.

Combining electronics + high & cycling temperatures what could possibly go wrong :s:

chris479
20th January, 2012, 01:54 PM
you guys know the score

VRPerformance
20th January, 2012, 02:23 PM
If it is just 'wear' all you have to do is adjust the actuator rod 10mm spannner open the lock nut and turn to make the rod longer .. done.exactly,will be bettar and safety than raise the SVBL from software ;)

furnata
20th January, 2012, 06:51 PM
Depends of what he wants - software or hardware decission ;)

VRPerformance
20th January, 2012, 07:08 PM
in that case,software will mean broken turbo's,the hardware will mean safety :)