Hey guys, another question!

I've a Mk1 VRS.

Running Standard all but a De-Cat and Blue Flame Cat back system.

Was put on the rolling road a while ago and got a nice healthy 191.7.

Anyway, the last few weeks, i've had a few problems.

When i accelerate, even gently and steadily through the boost, there's almost like flat spots - Like loss of power for a second, and then it'll kick back in!

It'll often do this a couple of times, more noticable when driving steadily.

I had a problem with a Lambda sensor, which i've removed, cleaned and re-fitted, the code for this hasn't come back up yet.

Obviously my engine managment light is on due to the Cat being removed anyway.

As far as i can tell, these aren't causing this issue, but there's no other Managment codes coming up, just the usual P1176 for Second lambda reading.

Any suggestions?

Is this a common thing or anything like that?

Also i've noticed fuel consumption was bad, i've cleaned the front lambda and it seems better, but may also be part of the same problem!

Cheers

Hmm, I noticed a little bit of a flat spot whilst my breather hose was broken. Now its changed it feels alot better.

At first glance it almost sounds like a n249 valve maybe even some blocked pipes?

I do have a breather pipe missing / Broken as it happens, but it seems a little major hesitation to be just that causing the problem.

Whats the n249 valve?

It might be the N75 but one of them affects boost if I am not mistaken?

I've never had a CEL for the 2nd lambda and I run a Blueflame decat and system.

Both the N249 & N75 control the boost in different ways.

The N75 controls the wastgate and if it is faulty I think it opens the wastegate too soon/leaks boost I think.

When mine was faulty I was down on power cos it wouldn't hold boost.

check all the vac/breather hoses for leaks/splits, theres 2 under the inlet manifold aswell around the dipstick.

have you tried a throttle body clean? plenty of threads covering this and many people get flat spots due to it being dirty.

check all the vac/breather hoses for leaks/splits, theres 2 under the inlet manifold aswell around the dipstick.

have you tried a throttle body clean? plenty of threads covering this and many people get flat spots due to it being dirty.

+ 1 for a split in a hose, I had a flat spot and found a spilt in one of those 2 hoses under the inlet manifold.

Fitting a boost gauge will help you diagnose it too.

Are you running a standard map? I'm wondering if that might be part of the problem. You've obviously reduced exhaust backpressure by a fair amount...

It's a closed loop system, so leaking breather hoses do have an impact on the running of the engine.

It's probably just a dirty throttle body though.....

This all makes sense.

Checked the CEL again today, and its come back up with the Code for Lambda sensor Bank 1

P0130 02 Sensor Circuit Malfunction (Bank I Sensor 1)

Would this cause the problem i'm having?

I'm thinking, Fix the breather, Throttle body clean, check the Vacuum pipes and eventually replace this sensor, and just hope this fixes the problem?

Yeah, its a standard Map, only mods being the De-Cat and Cat back system.

Cheers

I do have a breather pipe missing / Broken as it happens, but it seems a little major hesitation to be just that causing the problem.

Turbo's rely on creating pressure, if you have a split pipe this will cause a big issue. Defo get this changed.

Just put a thread up on this matter actually mate, i was getting confused with so many different things on one - All in, i've got a busy saturday coming up!

Cheers

Also noticed, the idle is horrendous...

Literally one minute it'll be a bumpy 600rpm, others its an uneven 900, and sometimes even 1000.

I've reset the EML 3 times with my reader today though, and every time its coming up front Lambda.

Looks like i've a lot of stuff to be doing over the next week or so - I have a few bits to do, breather pipes and so on, then onto the lambda and hopefully these'll all sort it!

iirc the front lambda will cause it to act up if it's failing as it wont be reading correctly.

Yeah i'm reckoning its that giving me such grief..

Not much point replacing until i've done the breather and whatnot though - Make it run spot on hopefully

Also, If when i get a Map, i decide to map the Second Lambda out, Will that make any difference to the car?

Some people have said it'll help ruin fuel economy just having no second sensor?

My EML is on for the decat.

Cheers

fuel economy doesnt drop too much unless you've got a lead right foot

mapping the CEL out won't make any difference to the car it just means you won't have a light on the dash all the while

mine was like this ... then i cleaned the throttle body ... cured the problem

it will cost u £2 something for a new gasket ... worth a try

Edited 17 January, 201115 yr by 550_VRS

Awesome, so Looks like i'm gonna need to write a thing or 2 down to get mapped out.. haha

SAI and Second Lambda are going to be the only ones i think if i'm correct?

That'll cover the N249 Removal and SAI?

Basically, If i remove all that crap the day before a Map, chuck a new Lambda Sensor on, Fix the breather and don't use any resistors and just leave the looms unplugged, what will i need to get mapped out?

Obviously if they're mapped out, it won't know they're there so won't cause any issues just leaving the plugs, correct?

Cheers

Yeah, I'm thinking time to get the pen and paper out...

Make a Decent list of what i need to fix everything, then buy the lot and just crack on!

whats it like when its cold ? my choke would start the car .. then run and drop off . then come back again until warm .. i then had a flat spot when accelerating like u described .. i followed the guide on here for cleaning the tb and its cured the issue .. now drives like when i first got it .. though mine had 118.000 miles on it

Got mine on 110k about 3 months ago,

Now has 117,500 on it!

Was given a Full service as soon as it asked, all but Fuel Filter i couldnt fit at the time, which i'll be doing shortly.

Occasionally from cold, will start, and cut out, 3 times then be fine on the 4th - Very occasional however.

Will idle around 12-1300 RPM From cold, and be uneven, sometimes even a little popping from the exhaust!

After about 2 mins it'll drop down to a VERY uneven idle around 900rpm..

Need to clean the TB me thinks, check the pipes around there for leakage and get that Breather fixed before moving on to any other mod..

it does sound like the tb ... try this before anything else as cheap fix ... my was exactly the same ( ish ) lol

Yeah, I can't find a guide on here even though i've searched, any ideas?

It can't hurt to clean it anyway!

Cheers

TB cleaning guide http://briskoda.net/forums/topic/129943-cleaning-throttle-body-1-8t-engine/page__view__findpost__p__1631514__fromsearch__1

TB cleaning guide http://briskoda.net/forums/topic/129943-cleaning-throttle-body-1-8t-engine/page__view__findpost__p__1631514__fromsearch__1

i followed this guide ... one thing it dont mention is watch ur knuckles as the edges are sharp lol