LEON CR fluttering boost problem

wilksy

tfsi
Aug 13, 2005
304
0
oxford
no 1 had any joy with sorting their problem yet then.
once i get time im gonna take a few bits off my car and see if there is anything suspect! ill see if i can check the waste gate aswell.
 

sargey

Escaped mental patient
Aug 16, 2006
324
0
Weston-super-crapland
any updated after cleaning the TB sargey? i've cleaned mine and its still the same i did it a bout a month ago. just been out it seems really bad today! would like to get it sorted before i have a map.

Scotty B did you get your car back?

Not tried mate. Im waiting for a local garage to get some more Forte TB cleaner (spray) and im just gonna spray some in and catch the run off. If its not a spray ill just take the lil bad boy off and clean it normally. I just cant be bothered to take it off and maybe have to replace the gasket as its prone to rip!

My boost guage was looking a bit sluggish last night for some reason. it was taking for ever to give a negative reading, checked all hoses only to find my DV was loose!!!! :confused: :wtf: :-o tightened it up and its not so sluggish no more. that was well dodgy!!

Im gonna get a N75J next week as i get paid 2moz and then ill clean the TB
 

wilksy

tfsi
Aug 13, 2005
304
0
oxford
may not be worth it mate as i've gota j valve on and at first yeah luvley sorted
but know its the same and i may have less power!
i moight get my tt tb cleaned up and fit that after having a look at the wastegate
 

sargey

Escaped mental patient
Aug 16, 2006
324
0
Weston-super-crapland
spose so. I thought a TT Tb wouldnt fit? How easy is it to check the wastegate as i can barely see the turbo so getting to the wastgate (depending on location) might be a bar steward
 

STEVEO@CYMRU

Lucky 7
Oct 19, 2003
310
0
CAERPHILLY S.WALES
Visit site
i might as well join in ..... i got a 2001 leon cupra and mine has been doing this for some time .......this is what i have done

new maf
new n75
4 new coil packs
4 new platinum plugs
dv regreased

and still its not any better......power then hesitation then masses of power and me trying to hold on
 

wilksy

tfsi
Aug 13, 2005
304
0
oxford
yeah i think the best way to have a look at the waste gate is to have a look from underneith. my worry is that the only way to see a problem is to take it all apart. as for a n75 steve i did the same and thought yes its ok ! but after two weeks it came back.
 
Mar 5, 2007
588
0
I noticed a slight, what could be described as a flutter the other day. I was going up a hill in 4th. I put my fut down full, then let up to about half/third throttle and when doing this, the car gave a flutter or shudder. I've felt it do this to a very small extent when letting of the throttle a bit, but this was the most pronounced.

Not sure how this stacks up with everyone elses experiences.
 

corradophil

Active Member
Sep 14, 2004
228
0
Essex
Room for a Golf here?

My AUM (same as LC AUQ) Golf was fine in standard spec, then I had it revo'd.

For the first couple of days it was great, then it seemed to be down on power in all gears. As the problem developed it also started hesitating which is particularly noticable in low gears at part throttle. I have also noticed that the fuel consumption is noticably worse when it's not running right.

I bypassed the N249 last week which cured it, then reverted back to std and the fault re-appeared. The N249 is now bypassed again, but this time although there is an improvement it still flutters.

The turbo can clearly be heard spooling up and down.

Everything on the car is standard except for the revo stage 1.

There are no faults showing.

I cannot find any leaks on any of the hoses, inlcuding the small ones going to the DV and vacuum reservoir.

Other things I have tried:

New N75F - no real difference.

Bosch Saab 93 DV which I have in the garage (Identical to original on mine except with a stronger spring) - Slightly different to drive, but it does not effect the surging fault. Neither DVs leak, when pushing the diaphragm and blocking the small connection on the top.

Good maf from a friends LC - Peak air mass rose from 162g/s with mine to 169 with hers, but no noticable difference in how it drives.

The N249 and N112 have the correct resistance across the coil, which is between 25-35 ohms. The non-return valve located with the N249 and N112 works correctly. The N249 seals when not energised, so I'm sure it is not this.

All that is left now is the actuator or turbo.
 

corradophil

Active Member
Sep 14, 2004
228
0
Essex
vw.jpg

Usefull diagram Feel.

Nobody seems to have mentioned the charge air pressure sensor (G31). Surely if this was giving a slightly incorrect reading it could cause the ECU to get in a muddle.

Can anyone prove or dissprove that this could be causing the fault?

Anyone know much about the G31?
 

corradophil

Active Member
Sep 14, 2004
228
0
Essex
Just had a quick look on mine while at lunch, the G31 appears to be mounted on the top of the intercooler, it's just visible in a Mk4 Golf, I assume it will be visible in an LC.
 

sargey

Escaped mental patient
Aug 16, 2006
324
0
Weston-super-crapland
to make matters worse my n249 mechanical malfunction has returned!!!
got ur car back scotty_b? i might Re-Do my bypass see how that helps me.
boost guage stopped workin yest, scared the crap out of me, only to find i had accidently trapped the hose to the guage with my fuse cover..worried for a sec there
 

corradophil

Active Member
Sep 14, 2004
228
0
Essex
has any1 tried the g31 yet to see if has any influence on what we are experiencing?

Not looked at the G31 yet but....

I put my old N75 back on yestrerday and tried adjusting the screw slightly, I could lose the surging by winding it clockwise but lost power. Turning it slightly anti clockwise incereased performance but made it surge.

Today the power was right down, I temporarily connected a pressure/vac gauge, which showed it was peaking at 0.3 bar of boost. The new N75 is back on and its hitting around 1.3 bar dropping to 1 bar at high revs. So far no surging, although it has been quicker. So I'll see what happens as the ECU addapts.

What is the specified max boost pressure I should see on a revo stage 1 AUM (same as AUQ)?
 

Scotty_b

Leon Cupra 300R
Jun 3, 2004
6,026
66
Hertfordshire
No its as was, i have some fancy requested v actual graphs but im not happy with how its spiking at all, hitting 26psi then tailing off to 21 and holding
 

wilksy

tfsi
Aug 13, 2005
304
0
oxford
Not looked at the G31 yet but....

I put my old N75 back on yestrerday and tried adjusting the screw slightly, I could lose the surging by winding it clockwise but lost power. Turning it slightly anti clockwise incereased performance but made it surge.

Today the power was right down, I temporarily connected a pressure/vac gauge, which showed it was peaking at 0.3 bar of boost. The new N75 is back on and its hitting around 1.3 bar dropping to 1 bar at high revs. So far no surging, although it has been quicker. So I'll see what happens as the ECU addapts.

What is the specified max boost pressure I should see on a revo stage 1 AUM (same as AUQ)?

would you be able to post a pic of your n75 as my boost was all over the shop tonight! i had it accelerate ok to 2200 2300rpm then it kicked in heavy and ionly had little pressure on the throttle, then later at about 2800 the boost cut again. i really am gonna have a better look tommorrow as this is now more frequent and more annoying! [:@]
 

wilksy

tfsi
Aug 13, 2005
304
0
oxford
the only good thing about tonight is i beat a porshe cayenne! :D
came to a set of lights and he looked over at me, didnt think about racing from the lights till an early mgf came steaming down the right sie of me [three lanes]
left the mgf standeing! close till i tried a bit harder and changed gear fast.
due to he age of the cayenne i presumed it to be a v8 as it was too close to be a v6 as i know my car can beat the 7.8 to 60.
 
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