fknbrkn
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mk4 1.8T AUM
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« on: November 24, 2013, 07:38:15 PM »
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Hello
I have a problem with air pressure dropping after 4000rpm
so its only
16psi @4700 (requested 18psi) and drops down more with 95% WDC (((
turbo is K04 hybrid (K04-022 CHRA with machined K03 hot side and K04 cold) maybe problem with that?
no leaks detected in system
fueling is ok
another way - stock cat-back after 3" downpipe
and there is stock 710n bypass valve, checked it - all ok
engine is 1.8t me7.5
little log attached
thanks
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overspeed
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« Reply #1 on: November 25, 2013, 06:55:20 AM »
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I have similar issue with customer, but his pressure drops till near 5psi.
in you case: Look channel 114 RPM = 4680 and 5120.
Note Spec load < spec load correc < Actual load
And 183Kg/s is a good mark without inlet and upgraded intercooler
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littco
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« Reply #2 on: November 25, 2013, 08:31:48 AM »
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Hello
I have a problem with air pressure dropping after 4000rpm
so its only
16psi @4700 (requested 18psi) and drops down more with 95% WDC (((
turbo is K04 hybrid (K04-022 CHRA with machined K03 hot side and K04 cold) maybe problem with that?
no leaks detected in system
fueling is ok
another way - stock cat-back after 3" downpipe
and there is stock 710n bypass valve, checked it - all ok
engine is 1.8t me7.5
little log attached
thanks
Try raising kfdimx if you haven't already. Other than that it might be your wastegate, if it's an old or weak one it might be struggling to keep the wastegate closed under high rpm/boost. |
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nyet
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« Reply #3 on: November 25, 2013, 10:54:39 AM »
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unplug the wg completely and see what you get.
if you can't build boost, you have a WG issue or BPV issue, or a boost leak.
if you don't see fueling problems, you either have bypass valve problems, or you don't have a boost leak..
usually this kind of stuff is trivial to diagnose because it likely doesn't have anything to do with the tune.
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fknbrkn
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mk4 1.8T AUM
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« Reply #4 on: November 25, 2013, 03:36:17 PM »
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overspeed, car have a fmic and AEM intake with tt maf housing. need moar!! littco, yep kfldimx is stock, i will try to playing with it. but if WGDC = 95% is there any reason to touch it? i see that is not accurately with some overboost @3000 still no time and knowledge to fine tune it. wastegate are pretty new come with turbocharger (~halfyear). how can i check it? by opening pressure test? nyet, i will try to accurately unplug WG.. scaring to blow something.. checked BPV by standart vacuum test - ok, trying to boost it by mouth to high pressure hole - ok (idont know how many psi i can build by myself))) fueling is ok, actual lambda is 0.75 in WOT same as specified try to find some leaks.. btw there is strange sound in part throttle when pressure at 0 psi (doesnt appear at negative and positive in any conditions) sound like poooo (not poo  ) going from engine bay, i know its stupid but maybe someone know what it an be. ive checked all piping with no luck thanks guys sorry for my english |
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« Last Edit: November 25, 2013, 04:24:24 PM by fukenbroken »
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RS-MAD
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« Reply #5 on: November 25, 2013, 03:55:41 PM »
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overspeed, car have a fmic and AEM intake with tt maf housing. need moar!! littco, yep kfldimx is stock, i will try to playing with it. but if WGDC = 95% is there any reason to touch it? i see that is not accurately with some overboost @3000 still no time and knowledge to fine tune it. wastegate are pretty new come with turbocharger (~halfyear). how can i check it? by opening pressure test? nyet, i will try to accurately unplug WG.. scaring to blow something.. checked BPV by standart vacuum test - ok, trying to boost it by mouth to high pressure hole - ok (idont know how many psi i can build by myself))) fueling is ok, actual lambda is 0.75 in WOT same as specified try to find some leaks.. btw there is strange sound in part throttle when pressure at 0 psi (doesnt appear at negative and positive in any conditions) sound like poooo (not poo ) going from engine bay, i know its stupid but maybe someone know what it an be. im checked all piping with no luck thanks guys sorry for my english First boost leak due bad crankcase ventilation hose under intake manifold . Its hard to diagnose because its too soft and when on idle vacuum close it and idle is good , when on boost you have massive boost leak from there. Second one is bad DV valve (blow off) , bad solenoid that control DV (I dont know what version is the car). And most of 1.8T Ive seen are with bad wastegate actuators due high temps and many km on them. If you have normal maf readings then I bet on your wastegate. Make like Nyet says to you but dont full throttle on 2000 rpm the car , just soft and wot uptop. If there is no diff in your boost then just short wastegate actuator rod. |
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fknbrkn
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mk4 1.8T AUM
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« Reply #6 on: November 25, 2013, 04:21:27 PM »
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i ve replaced all breather hoses and valves
thanks for detailed advice, i will check DV solenoid and try to run with unplugged WG
maf doesnt look faulty, its 1y old bosch unit
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20VTMK1
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« Reply #7 on: November 29, 2013, 09:42:44 AM »
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Unplug the n75 - you wont blow anything , it will run off WG pressure - this will give you a good idea where the boost is for PID control.
You can check the crack pressure as well , if this is low then its possible for the WG to open at high rpm with high exhaust flow .
As I understand , KFLDIMX can be what it is and yet you will still get max WGDC , KFLDIMX feeds into the PID controller . So in this sense you can adjust KFLDIMX up in certain areas for a higher base WGDC
Correct ?
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fknbrkn
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mk4 1.8T AUM
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« Reply #8 on: December 07, 2013, 10:09:27 AM »
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so today im checked N249 solenoid - its ok, no leaks, open & closes correctly. checked WG - ok, no leaks. but can not give specified pressure to it. so i dont know minimum opening pressure. still cant drive without WG because have no time or heavy snow  |
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« Last Edit: December 07, 2013, 10:11:22 AM by fukenbroken »
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nokiafix
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« Reply #9 on: December 07, 2013, 02:06:45 PM »
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Pressure drop from ineffective charge system flow, or your turbo intake pipe may not be up to the job to flow the v
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nokiafix
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« Reply #10 on: December 07, 2013, 02:07:41 PM »
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Could be a Pressure drop from ineffective charge system flow, or your turbo intake pipe may not be up to the job to flow the volume of air needed.
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terminator
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« Reply #11 on: December 07, 2013, 04:14:16 PM »
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I had a lot of problems with used K03 after 4000 Rpm. Dead turbocharger was the problem. Though 18 psi for K04 gybrid is not so much, but I believe its either problem with turbo or with your file.
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fknbrkn
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mk4 1.8T AUM
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« Reply #12 on: December 07, 2013, 04:37:28 PM »
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Pressure drop from ineffective charge system flow, or your turbo intake pipe may not be up to the job to flow the v
there is only one restrictive place - turbo inlet. pipe is silicone from frankenturbo with TT maf housing and AEM dryflow filter. so if typical K03/K04 can rich more, than <i think> mine too I had a lot of problems with used K03 after 4000 Rpm. Dead turbocharger was the problem. Though 18 psi for K04 gybrid is not so much, but I believe its either problem with turbo or with your file.
as i can understand file cannot be a problem because WGDC = 95% (max) so WG must be closed turbo.. maybe. this is hybrid and who knows how it works, but this is not old one. |
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terminator
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« Reply #13 on: December 07, 2013, 07:08:36 PM »
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I saw 22 psi on K03 turbo with standart pipes. Though its not ok for K03, but I mean pipes are not so important. I installed K04 and made a holl into air filter box (like RS4 box now but without flap ). You can check catalyst also (if its still installed) and N75. But I think the problem with the turbocharger. |
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prj
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« Reply #14 on: December 08, 2013, 02:10:39 AM »
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Rule 1: before you tune ANY turbocharged car, you pressurized the entire system with a compressor at the MAF->Turbo hose (preferrably bypassing PCV).
You have not done this yet? GTFO the forum and make sure Rule 1 is checked correctly.
Any time you skip Rule 1 on a mass-flow ECU you will just waste your time and your tune will be worthless.
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