Emissions fail

[Monkgti]

well lads, having trouble with my vts, when i bought it from a fella it had failed nct on emissions, so i got it put a new cat in, had it checked and they were still too high, so bought a new lambda put it in they were still too high, so after checking the timing i found the belt was a tooth out on the exhaust so i sorted that, i also gave the car a full service, took all sensors off and clen them, and clen the throttle body, put emissions stuff in the petrol had the car put on diagnostics and no fault showing up, even took off the induction kit and put standard air box back on and still failing emissions. its the CO that is failing its just on the limit on idle and its double the limit on 2,800rpm. i dont know what else i can try at this stage, has anyone else had problems like this??

[stevo67]

When you put the petrol treatment in?Did you take the car for a run down the motorway then gave it to the garage with a warm engine(still running)?

[Monkgti]

i did i gave it a really good reddining before i got to the nct centre, and when the fella was in testing it he even kept it on the machine for ages incase it needed to warm up more but still failed

[Futurism]

It Putting out any smoke?

You got the right oil in? Is it too full?

Mines failed on just this and it's failed piston rings, mine still had compression was just the oil seal that's gone, (though mine is a 1.1 8v)

[Monkgti]

no lad, not burning any oil and not a bit of smoke atall, ive 10w40 total oil in just dead on full mark and ive just gave it a service including iridium plugs... the only thing is you can smell that its running a bit rich on fuel.....

[Futurism]

Any deposits on the old plugs?

[Monkgti]

no none, bone dry and they wernt even that black just normal dark brown colour... i cant understand it atall, and the car is running fine just sometimes on idle its a bit uneasy, but my 106 was the same even after fitting all new sensors to try fix it but it still passed emissions with no problems...

[Futurism]

You changed the fuel filter?

Does it have 2 lambda sensors or just the one? Cause if there's 2 and they are plugged in the wrong way round that can cause over fuelling,

Apart from that from what I've read, could be a dodgy injector but I don't know how to check for this,

[Monkgti]

yep, fuel filter changed aswell, it just has the 1 lambda in the downpipe... ive got a loan of a map sensor and TPS from a gti so just going to get it checked this eve with them on to see if its any better...

[Futurism]

Try your blue coolant sensor aswell, was reading the other day that if it's broke it will give the ecu the wrong reading which will in result change your fuel ratio, longshot but it's pretty cheap

[Monkgti]

ive spent the whole day yesterday at the car and still wont pass :wall:
ive tried everything, every sensor, 2 cats, new lambda, checked timing, even moved around the pulleys while on the emissions machine, checked fuel pressure, done comp test, checked every vacume hose for leaks and no difference, i dunno what else i can check, the ecu hasnt been opened so not chipped, had it on diagnostics and no faults and all sensors are reading correct.. one more thing im checking is the inlet mani, i got a loan of one and put it on last night just waiting to bring it to check emissions again today.... if this doesnt work i may just give up, i dont know what else to try?

[NismoSteve]

That's a crazy situation there mate:( doesn't seem to be anything else to change, is the rest of the exhaust all sealed okay? Is the throttle body clean, stepper motor seal okay? Try going round with some brake / carb cleaner squirting it all round the throttle body / inlet. Might be a tiny air leak somewhere?

[MrJames]

Might be worth taking a look at the ECU? If the ECU has gone faulty and not reading the data from a sensor or any other number of problems it will cause running problems had this on an astra before :wacko:

[stevo67]

An outside chance this mate but you could try another ecu(unlocked 1)tbh i`m running out of ideas as you`ve tried everything.Another thing to try is unplug the battery for 1/2 an hour.

[Monkgti]

yep the exhaist is all ok, no leaks anywhere, and ive cleaned all the throttle body and sprayed carb cleaner everywhere to look for leaks and none atall, even changed the whole inlet incase there was a small crack i couldnt find, also disconnected the bat aswell for a while everytime i changed somthing, even tried different petrol, higher octane rated stuff and nothing makes any difference :wall: one strange thing is though that on the way back to try the emissions i really reddined the car, left it hit the limiter in 2nd for about 5 seconds before pulling into the garage and put it on the machine straight away and all readings were as low as they could go, even on high idle they were well below the limit, so i said just turn the car off for a few mins as it would be in the nct centre before they bring it in to check, and when i started it after 5mins the co was back up at double the limit again :( i think the ecu is the last thing left to check alright is'nt it? it doesnt look like it was opened before but i wonder would it of been remapped or mabey it is faulty then...

[Futurism]

You are seriously unlucky mate, I can't think of anything else to try,

I'd say ECU as said before would be your next bet. I'd do that and then get it back on the diagnostics machine as there could be a problem and the ECU might just think everythings ok. I'd also check all your engine fuses and grounds just to check, could be anything now lol.

Deffinatley sounds like over fuelling though, which would make sense when you revved it up ad it was ok as all the fuel would have been burnt off. Think that makes sense,

[jones91]

I reckon by the sound of it, the old owner could have put one of those cheap eBay +"insert Bhp figure" chips in, which make cars massively overfuel.

That's really all I can think it could be

[Gandi699]

What fuel pressure regulator are you running and are they standard vts injectors?

[Monkgti]

got a loan of an unlocked ecu tonight so goin to try that tomorrow now to see if theres any difference, after that im out of ideas :(
standard regulator and injectors and they have even been changed when i changed the inlet mani last night and made no difference atall..., put a guage on the fuel line and its reading just bang on 3 bar

[Gandi699]

Might be a long shot but take it to a different garage and see what they say? I take it you are getting the cat hot, and I mean very very hot before the test?

[Monkgti]

well ive had it at the garage where im doing the work on it but at the nct centre its showing up the exact same readings... yep bringing it for a few mile spin before checking and its well hot every time... the lambda and HC readings are perfect its just the CO that wont go down :wacko:

[Monkgti]

just back from having it checked again with the different ecu and still no difference :(

[Monkgti]

i have iridium plugs in, would they effect it if the temp rating on them was wrong??

[Monkgti]

checked car again and it passed, left it for 10mins checked again and still passed!! does anyone want to have a guess at what it was!?? the last and most simple thing i tried....

[JoshB]

Put the probe up another cars exhaust?

[m11ler]

Tell us then lol

[saxova]

old rags in the backbox?

[Monkgti]

the plugs! i read up about em last night and the correct iridiums are BKR6 but the lad in the factors gave me BKR8, 2 grades cooler plug, i only realised when i took them out to check today, so i put an old set of standard plugs in and it passed straight away :)

[Futurism]

Glad to hear this is sorted mate =]

[NismoSteve]

Face palm moment, I guess it was always going to be something simple. Pleased its sorted mate. Must have been a relief.

[Monkgti]

aw it surely was, but to realise it was the plugs, there somthing i never would of thought of especially as they were brand new and the car wasnt missing or spluttery or anything

[stevo67]

Glad you got it sorted mate.