N75 valve & boost probs

[cupra-c_ya]

Hi there,

I have just changed my N75 valve as I was having fluctuating boost probs, since putting the new one on my car seems more hesitant and is not pulling like it should, the turbo does not seem to be spooling up properly.
what could be the reason for this, I thought it would run better?
any ideas guys, should I log N75 duty cycle or any other blocks?

the N75 valve is the same 'F' valve as on the car before

 

[cupra-c_ya]

any help on this guys?

 

[Martyn]

Log blocks 002 or 003, 020 and 115.

4th gear 2k to 6/7k please foot to the floor please bud

 

[cupra-c_ya]

Hi martyn,

really weird mate, really hesitant up the rev range, I have changed the spring in my dv to the green from yellow recently as well, is it worth putting the yellow back in?

will do some logs with my brother tomorrow, surely it cant be maf again?

martyn I accidently did a fault scan on the engine whilst the engine was running, will this do any damage as it is advised not to scan with the engine on, did come up with 11 fault codes?

 

[Martyn]

Hi bud, I'd put the yellow back in and see it makes any difference. I wouldnt have thought it would but it's worth a go.

Anything is possible, get some logs if you can, it'll help determine the problem.

As for the 11 fault codes....what were they? I've checked the engine for fault codes whilst the engine is running and never had a problem.

Cheers,

Martyn

 

[cupra-c_ya]

just going to get the logs off the laptop as on the home pc, some look to be serious and this could be why im having my problems, will post shortly mate BRB.......

 

[cupra-c_ya]

here we go martyn the dreaded fault codes, I think this could cost me some major ££ to sort out?

what do you think....

Wednesday, 22 March 2006, 17:49:49
VAG-COM Version: Release 409.1-US
Control Module Part Number: 06A 906 032 DE
Component and/or Version: 1.8L R4/5VT 0001
Software Coding: 11510
Work Shop Code: WSC 12856
11 Faults Found:
17633 - Fuel Injector for Cylinder 1 (N30): Short to Ground
P1225 - 35-10 - - - Intermittent
17635 - Fuel Injector for Cylinder 3 (N32): Short to Ground
P1227 - 35-10 - - - Intermittent
17636 - Fuel Injector for Cylinder 4 (N33): Short to Ground
P1228 - 35-10 - - - Intermittent
17634 - Fuel Injector for Cylinder 2 (N31): Short to Ground
P1226 - 35-10 - - - Intermittent
17833 - EVAP Purge Valve (N80): Short to Ground
P1425 - 35-10 - - - Intermittent
17955 - Boost Pressure Regulation Valve (N75): Short to Ground
P1547 - 35-10 - - - Intermittent
17525 - Oxygen (Lambda) Sensor Heating Circuit: B1 S2: Short to Ground
P1117 - 35-10 - - - Intermittent
17843 - Secondary Air Pump Relay (J299): Short to Ground
P1435 - 35-10 - - - Intermittent
17938 - Camshshaft Timing Adjustment: Short to Ground
P1530 - 35-10 - - - Intermittent
17829 - Secondary Air Injection Solenoid Valve (N112): Short to Ground
P1421 - 35-10 - - - Intermittent
17697 - Boost Pressure Control Valve (N249): Short to Ground
P1289 - 35-10 - - - Intermittent

 

[CupraSteve]

a dodgy earth somewhere?

 

[Martyn]

Clear the codes, take the car for a rip and tell me if any of the codes come back mate.

 

[cupra-c_ya]

will go clear then come back to you martyn, what do you think so far, looking grim?

 

[Martyn]

Like Steve said it could be a bad earth, we'll worry if they codes come back....

 

[cupra-c_ya]

martyn I have done as you suggested, no fault codes at all.
could this of happened because I unplugged the N75 valve? If these re-appear could it be a wiring prob?

I will do some logs tomorrow of the suggested blocks and see what these bring up.

might never get to the bottom of this problem, could it be a faulty N75 valve that has been sent to me I wonder

 

[Russellg911]

Join my 'sporadic boost club' dude


At the moment I'm having to let my revs sweep back and forth between 1,5k rpm and 3k rpm to get a half decent boost. Whatever's supposed to be 'activated' in that rev range, isnt being (about 5 times out of 10). You either get the kick and a nice pull through the range, or a kick which then runs out of breath around 4k rpm (and feels flat) or just no kick at all. Doing my head in.

 

[cupra-c_ya]

doing my head in as well matey, boost creeping in/out and flat.
Got my brother to drive it earlier on and even he said it felt hesitant up the rev range, my brother drove my car when it was running sweet before. (those were the days!)

My brother has a clio 182 and the way my car is driving at the mo he would piss all over me, he would beat me around the twisties anyway.

*edit* does your car drive o.k if booted through the gears or does it fluctuate in every gear?

 

[CupraSteve]

i reckon the n75 is the answer to all your problems

 

[cupra-c_ya]

steve, so you reckon the N75 is the prob? will do some logs tomorrow.

do you think it is worth trying a different N75 like the J?

I think ive got a dodgey new N75 valve, will ring vag parts and say that car is now worse then before, same valve which was on my car before 'F' variant

 

[Russellg911]

C_ya:

If I boot it through each gear it doesn't hesitate but can feel stretched when pushed past 4krpm.

It's when I'm easing my way through the lower revs that it either catches and pulls cleanly, or just seems to stumble?!

 

[cupra-c_ya]

I take it your car can make it to the red line?
did you get the N75 valve off the chap on here yet?


mine just hesitates up the rev range, almost like the turbo spools then cuts spools then cuts and so on, hesitant. not smooth power delivery like it has done in the past.

Im just wandering if you can get dodgey N75 valves as mine has been running worse then my old one?

 

[Pabs]

right well, heres my opinion-

I had problems with my car a while back - boost fluctuation where the boost would bounce between 10-20psi several times before settling down at max boost when flooring it.
To fix, I changed the N75 valve. I changed from std F variant to a new F variant (new as in component age). This seemed to improve the problem 80% - hardly saw the issue after that, but it was still there briefly.

I have, recently, as in the last week, seen this problem reoccur. Not sure what it is.

However, Revo's advice is (if you've got it) to leave the n75 as STD - not a J or whatever - they write the code for the std F and changing it would c*ck things up. 99% of the people on these forums would agree - only ChrisUK reports his to be fine, everyone else is back on F variant.

I'm going to check mine for errors this weekend, and do a TB Alignment again. If possible going to get a TB clean done soon too. And then if all else fails start looking at the N249 bypass and such, or perhaps replace the n249? Who knows

 

[Russellg911]

Ok take today.

Driving to work and open stretch of road. Am cruising in 4th gear (just under 2.5k rpm) and firmly start to plant my foot; not much of a nudge at it revs just over 2.5k but I carry on accelerating past 4krpm and car just feels 'wheezy' by now....i then hold it at around 4.5k rpm for a few seconds and then press down on the throttle again...and then you feel a lovely boost of pressure and the car happily pulls to near the redline....like somthing has become unblocked.