Why do singles smoke a fair bit then?

Is it something to worry about, or is it a result of not having cats, or...?

AFRs are fine & dandy BTW.

Mine did as it was overfuelling like mad but now remapped by RyanG and idle control valve fitted and so much better. Who mapped it?

Is it something to worry about, or is it a result of not having cats, or...?

 

AFRs are fine & dandy BTW.

not noticed mine smoking, the only time it did was with a split pipe, running rich or oil seal i would guess;)

It should not smoke at all, only time mine smoked was when i had a cracked piston ring.

It should not smoke at all, only time mine smoked was when i had a cracked piston ring.

err and on burnouts:D

Mine did as it was overfuelling like mad but now remapped by RyanG and idle control valve fitted and so much better. Who mapped it?

lol, Ryan G

It doesn't smoke all the time, just the first time I hit positive boost after an extended period of driving off-boost (and maybe the car being parked up for a few days.

Black smoke, not blue. I think.

Black smoke is fuel so may need a tweek of the map.

Black smoke is fuel so may need a tweek of the map.

Hmm ok, cheers Jamie.

Why would it smoke only after periods of non-boost though?

Also - wouldn't it show up on the AFR/wideband gauge jobbie? Not that I can look at it for long, nor can I actually get WOT yet, but I don't think it's been lower than 11.2~3ish (under load).

Hmm ok, cheers Jamie.

 

Why would it smoke only after periods of non-boost though?

you could also have a slight boost leak

you could also have a slight boost leak

*thinks about why that would make it run rich* Doesn't the ECU sort fuelling out, regardless of whether the achieved boost matches the expected boost or not?

On other matters, is a T67 smaller/bigger/'different' to a GT40?

I doubt its a boost leak, might be dodgy O2 sensor.

Maybe a bit rich in overrun or light throttle\low load, then when you give it the beans it clears it all out ?

Maybe a bit rich in overrun or light throttle\low load, then when you give it the beans it clears it all out ?

Hmmm that might be it.

I'll experiment more

on cold start mine has light white smoke, which goes when up to temp.

i have no idle control valve, where did ryan get one from?

on cold start mine has light white smoke, which goes when up to temp.

 

i have no idle control valve, where did ryan get one from?

dunno, t'was all done before I purchased.

valve stem oil seals and the smoke colour wasn't picked up properly?

Black smoke is excess fuel, blue smoke is burning oil, it should produce neither.

The overrun on your car only cuts the fuel above 3000rpm to keep the round the town driving smoother so when you lift off under 3000rpm it will be abit richer like 12:1 but nothing to produce any smoke.

Does sound to me like stem oil seals, As when you drive around off boost etc the engine is under vacuum most of the time and when under vacuum it sucks down the oil into the combustion camber. Will be more noticable when cold and would also explain why when the first time you boot it you see the smoke.

A good test would be to cruise up to say 70mph in 3rd and then lift off off the throttle until the revs drop to 3.5k then put your foot down about 75% throttle and see if it smokes.

Ryan

on cold start mine has light white smoke, which goes when up to temp.

 

i have no idle control valve, where did ryan get one from?

Thats condensation in the exhaust

I will speak to you next Thursday about the Idle control valve mate as have found a cool little trick for cars with out them.

Does it use map and tps to calculate load?

Thats condensation in the exhaust

 

I will speak to you next Thursday about the Idle control valve mate as have found a cool little trick for cars with out them.

oooh sounds good

A good test would be to cruise up to say 70mph in 3rd and then lift off off the throttle until the revs drop to 3.5k then put your foot down about 75% throttle and see if it smokes.

 

Ryan

Cool thanks Ryan - I'll try that when I'm next out in it. trying to keep the miles down (to zero, lol) till it's serviced and had the geo setup, so I don't cause any damage or unevenly wear the newish fronts.

Does it use map and tps to calculate load?

Pass - Ryan?!

Thinking about it Ryan - could the poor cold-start running be causing the smoke? I'm wondering if it runs rich during that period then when I first give it some boost 10 mins down the road....

I need to upload the map you gave Jake (and he gave me on a DVD) but don't have the necessary lead - I meant ot ask what I need (MoTeC M600).

Ta!

Steve I have seen yours and know what you mean, it does like to clear its throat out, but thats all I think it is......it clears, and like you say its after driving off boost, I think it sort of cokes up a bit maybe due to what Ryan said about being slightly over fuelled.

Its deffo not valve stem though, I have valve stem issues and like others say it gives off a definite plume of smoke on over run sometimes and when first starting up, soon to be sorted though. But even I notice if I drive around on just one turbo, changing before 3k all the time then, then when I first run no.2 its like she is a bit coked up and really clears her throat, but then Im sure mine is over fueled a bit, despite Thor adjusting my fueling saying they trimmed it down.