help please on low boost

[coatesy]

i had a problem with a bad idle when coming to a stop at traffic lights and round about's the same as dani has in the s3 - (Seriously at my wits end now...........)

i have solved it about three times now firstly i checked all my boost and vac pipes some of them needed tightening up so i did this,

second time it came back i changed all the vac pipes for new silicone ones and changed the plugs and temp sensor ( as the car was reading that the engine was -10 all the time) this then sorted the job out.

third time around i changed my fuel to super unleaded and fitted a boost gauge to see if there was any leaks, after fitting it i checked every thing again scanned it with vag-com it was sound no codes. i was also boosting 6-8 psi which if im right is normal for an unmapped AGU.

in the past week or so the bad idle has come back again but when i come to a stop if i leave the car in neutral and don't have the clutch in, it doesn't through this bad idle thing, also it depends what gear im in to what boost reading im getting on the gauge in 2nd i get some times the 6-8 psi but in third it will drop to 3-4 psi, also a slight burning smell when inside the car but when i pull over the burning smell isn't from the engine bay well i cant smell it when i stick my head under the bonnet. nearly forgot to add it feels quite lumpy when driving.

if its bad news that's not to worries, currently in the middle of saving and creating a list and gathering info for the k03s hybrid its getting when the weather gets a bit warmer, this will be along with an engine rebuild and rods and so on.

any help is muchly appreciated.

car is an a3 1.8T 1997 AGU

[Alais DJA]

what car is it? make / model

[coatesy]

its an a3 1.8T 1997 AGU

[Dani_B19]

Mate, i think are cars are juat linked.

Ive got the same problem, mine used to make 11psi in higher gears etc and 14psi when raged from lower gears, now it makes around 9psi, 10 tops, if i raged it in lower gears i may see 12psi.

Its doing my tits.

Can i ask, does your agu engine have a sai?

[coatesy]

no i dont believe the agu cam with a sai, its just basic as feck but gay as people that go to pen island .....

[Benjiman46]

Ok first of all what's your MPG like mate?

If it's normal, try disconnecting your MAF sensor, driving it and seeing if it makes it better. If it does, then you have a faulty MAF. Get it changed and your massive 6-8 psi will be restored

Ben

[coatesy]

Ok first of all what's your MPG like mate?

If it's normal, try disconnecting your MAF sensor, driving it and seeing if it makes it better. If it does, then you have a faulty MAF. Get it changed and your massive 6-8 psi will be restored

Ben

haha hell yeah my massive 6-8 psi goes borrp tishh ....

its like 27 mpg don't really go for to work in it and don't boot it every where. im not to sure if its about right but it used to be 22-24 when the temp sensor was playing up

[Dani_B19]

When you temP sensor was Playing up, did you have dodgy temP readings or any fault codes?

[coatesy]

i got the car scanned by this massive snap on scanner thing, and i don't know if you can do this on vag com but it brought up a list of the things on the engine and next to the item in the list it said if it was okay or not, and the temp sensor said next to it engine temp -10 so the bloke said your car thinks its minus 10 so its mega over fueling, so i changed the temp sensor and the spark plugs now it reads as it should

[Dani_B19]

Argh, ok.

Also to ad, the car doesnt drop revs if only using part throttle or under, if you use full throttle or go above 2000rpm it does it, ooh and also, it only does it when cars upto temp, never does it when cold.

[coatesy]

im pretty sure mine only does it when warm also ill find out tomorrow

[Dani_B19]

Strange int it mate.

[coatesy]

car starts to do this after its been running for about five minuets, but like said above it doesn't do it when coming to a stop in neutral, also my clutch pedal feels massive as in the bite is at the top of the pedal, i think its been like this since i had my new clutch put on, also the pedal is very light im not sure if this is supposed to be right.

[coatesy]

did a bit of research and found on other forums that people had cured this by changing the clutch switch and or cleaning the TB and getting it aligned, dani has tried all these things and none of them helped.

can anyone actually help or is it just a sh*t problem that know one knows.


also would i have a clutch switch on my car if so would it be the two pin one ? i read earlier that not all cars have them and there are two types.

[s3dave]

I dont think there as ever been a definitive solution to this problem, it does seem to effect mapped cars more i believe..
I just live with it, it only does it now and again, (It does make you look a complete prick sometimes...)

[Dani_B19]

Do think its because my car isnt mapped and its narrowband.

So far ive got a huge jetex filter, enlarged boost hoses, 008dv, full 3" TBE. Do you think the ecu is going abit wappy as it isnt mapped to cope with the supporting mods?

[stumpy83]

iw ould prob agree with you on that last comment. it seems a very good posibilty that you have a lot of aftermarket add ons there, perhaps its getting a bit confussed?? it could be possible hey???

[coatesy]

My car isn't mapped either, and its got pretty much every add on mod I could bolt on apart from a bigger turbo, I'm going to re apply everything iv done to the car just to make sure its not me making any mistakes.

I could just live with it until my hybrid build starts but I'd be pretty pissed if it still did it after a new turbo and a rebuild

[Dani_B19]

Ooh ive also got a b5 tip too .

[coatesy]

little update, i cleaned the TB yesterday, well could say super cleaned it there was lots of build up on the butterfly, got the cotton buds on the go with some wynns throttle body cleaner on the job after about 10 mins spraying and cleaning got it back on the car reset the TB,

also unplugged the speed control sensor or idle control sensor cant remember what it was called but anyway i forgot the plug that back in, which brought up a fault code when i scanned the car, anyway plugged that back in, also cleaned my DV as it was full of rammy sludge.

took it for a drive all was good no more dipping in revs when coming to a stop. seems to be all good today as well, hopefully it will stay that way.