Help please !

[Jackcookiecook]

Since I've owned my s3 8l it's been nothing but trouble , need to your brains guys , first off my car will hit 2/3k then splutter and goes flat and no faster I'll let off and it will pop and bang and gurgle then it will let me go faster but it's un drivable , I'm getting 6mpg and there is fuel up my bumper I've tried new plugs and maf sensoralong with n75 valve and checked vcds and no faults stored -.- I really am stumped with this one and no chance of a vak leak as I had it smoke tested .... Any idea guys

 

[daz-20vt]

Is it like a miss fire?
Coil packs?

 

[Jackcookiecook]

Yeah kind of tbh, but will rev all way round when not under load , as soon as driving in gear it throws a hissy , I eliminated misfire as due to when I unplug the n75 it will drive like a normal 1.8 with no hiccups

 

[Nilz]

First things first, get it scanned and get us some fault codes. If you rev it can be fine, under load if it's popping it could be coil packs.

Get the scan done as it will help you and us and save money too.

 

[Jackcookiecook]

I did scan it with vag com/vcds, only fault thrown up was the n75 as I unplugged it when it was running

 

[Nilz]

So it drives ok with the N75 disconnected??

 

[Jackcookiecook]

Yeah it drives okay like that

 

[Nilz]

I would say that its a faulty N75 valve then, however if it was that, it would have come up when you did a scan.

 

[Alan Gunn]

Is it possible to get the pipes the wrong way on the n75.
Just a thought.

 

[<tuffty/>]

Needs logging... could be over boost causing a soft limp, could be failing coil packs but this tends to carry on misfiring after the initial splutter...

Could also be a failing fuel pump..

What year/engine code is the s3? is it mapped? other mods?

Fuel up your bumper? I assume you mean being spat out the exhaust?

However based on the symptoms you describe it sounds fuelling related.. could be a blocked fpr causing the pressure to rise artificially... driving on actuator pressure doesn't really prove much other than its more ****** off when there is more boost

<tuffty/>

 

[Jackcookiecook]

I also thought over boost so I re adjusted the actuator, and checked for block n75 tubes

And yes I meant out if the exhaust ,

New update though battery warning light come on and died mid drive so I replaced the alternator as I had no charge and also with a silver Bosch battery , but only seeing 11.3 v I checked all earths and lives to starter all clean and okay , I have 0.1 resistance between earth so that's good , mind boggled , runs better now but still spluttering , after that I got open circuit injector 1&2 but never come back

I think replacement fuel pump also as maybe lazy along with a relay as it will only prime once and not by the door

It's a 2002 bam with no mapping and only mod is a oil catch can from crank and rocker to atmosphere

 

[Greg-S3]

Have you checked the tip isn't collapsing? I had a Golf 1.8t with similar issues as you and it was my tip collapsing! When was the fuel filter last changed? What's the miles on the car?

 

[Jackcookiecook]

120k but it's had a rebuild as in all new rings and seals and valves and bearings oil pump etc , and most recent about 3k ago as I also thought blocked filter , as it takes a couple of goes to start like it's not holding rail pressure or building ! Might be worth putting a silicone one in place you reckon

 

[JUS3IN]

clean the earths under the battery. these can cause all sorts of weird shiz and always get corroded. 6mp is terrible, if your not throwing any codes its likely a mechanical issue so follow tufftys advise, get a garage to test fuel pressure.

 

[ayfreetee]

I would have said it is alternator, you may have replaced it with a faulty one, it does happen.

 

[Jackcookiecook]

I will phone euros tomorrow and say the alternator is faulty and want a replacement I went Bosch and in case of this and it cost me £240 I already cleaned the earths and live off the starter