Smoke on acceleration - again
Discussion
So, coming out of a roundabout onto the A11 yesterday I gave beastie a bootfull in second gear. I had to do this because a mate was behind in his Mustang 
Anyway, crap loads of smoke issued forth under hard acceleration 
He later told me it looked a bit greyish, although from where I was sitting it just looked extremely dark. I don't think it's overfuelling. I also don't think it does this everytime I floor it, but I may be wrong. I'm wondering if the surge of oil towards the back of the engine is causing a problem in the rear cylinders, although that's probably nonsense and wishfull thinking... So, I'm thinking maybe a leakdown test....
Any thoughts chaps?
Anyway, crap loads of smoke issued forth under hard acceleration He later told me it looked a bit greyish, although from where I was sitting it just looked extremely dark. I don't think it's overfuelling. I also don't think it does this everytime I floor it, but I may be wrong. I'm wondering if the surge of oil towards the back of the engine is causing a problem in the rear cylinders, although that's probably nonsense and wishfull thinking... So, I'm thinking maybe a leakdown test....Any thoughts chaps?
phazed said:
Valve guide seals sucking oil on the over run and then dispensed under hard acceleration?
Oil in catch tank being sucked back into plenum?
Bores need honing?
Overfueling under hard acceleration, (have you a wideband gauge to check?)?
As above, log running on laptop and analyse.
Thanks Peter, off to Abergloom tomorrow so it's gonna have to wait for a few weeks now Oil in catch tank being sucked back into plenum?
Bores need honing?
Overfueling under hard acceleration, (have you a wideband gauge to check?)?
As above, log running on laptop and analyse.
Does it remain constant/continuous or just a rush of grey smoke? it may be excessive/incorrect AE/acceleration enrichment I have seen maps with excessive use of this up until a point its undetectable & because the Wideband don't detect it quick enough can go unnoticed unless its so rich it causes stuttering/fluffiness in the delivery 
if it was oil burning it generally hangs around for longer and is a bluish haze then refer to Peters post 
though really without seeing its hard to say quite honestly 
up until a point its undetectable & because the Wideband don't detect it quick enough can go unnoticed unless its so rich it causes stuttering/fluffiness in the delivery if it was oil burning it generally hangs around for longer and is a bluish haze then refer to Peters post though really without seeing its hard to say quite honestly Edited by Sardonicus on Monday 2nd September 15:46
Sardonicus said:
Does it remain constant/continuous or just a rush of grey smoke? it may be excessive/incorrect AE/acceleration enrichment I have seen maps with excessive use of this up until a point its undetectable & because the Wideband don't detect it quick enough can go unnoticed unless its so rich it causes stuttering/fluffiness in the delivery if it was oil burning it generally hangs around for longer and is a bluish haze though really without seeing its hard to say quite honestly
Very interesting up until a point its undetectable & because the Wideband don't detect it quick enough can go unnoticed unless its so rich it causes stuttering/fluffiness in the delivery if it was oil burning it generally hangs around for longer and is a bluish haze though really without seeing its hard to say quite honestly 
When last mapped it was massively overfuelling due to a faulty air temp sensor (now fixed), but was also over the top on acceleration fuel enrichment so it was wound back a bit. This was back in December, but although the remap smoothed out the low speed running & idle etc we couldn't do WOT runs as the roads (sorry, runway) were too damp... Since then the main cat has also been removed I've got the map file and was supposed to do some logging under WOT then send the log file back for assessing.. but I haven't yet
Chilliman said:
Goaty Bill said:
Based on your other thread, I would guess you spilled some polish somewhere
Haven't you got an allotment to play with? I still think, given your obvious lack of previous experience (current reasonable effort notwithstanding), that my suggestion should be seriously investigated
TVR Beaver said:
Can it suck back from a catch tank??... is the tank full??
oil usage sounds okay unless a valve seals come off?... does it do it all the time now.. or just that once?....
how many miles on your new engine?
Can't be from the catch tank it's not currently hooked up to the plenum. I don't think its doing it all the time, but going out for a play shortly so will try and see what happens.. oil usage sounds okay unless a valve seals come off?... does it do it all the time now.. or just that once?....
how many miles on your new engine?
New engine is just on 10k now...
Right, played around a bit with varying throttle inputs, and it seems to be that using progressive throttle input down to WOT doesn't produce the same (if any - hard to tell) smoke as stamping on the accelerator. I'm thinking that this ties in with Sardonicus' suggestion that maybe the ECU is lagging behind throttle position? The Lambda is downstream of the Y piece, don't know if that's a contributing factor... No smoke on over-run though... I can also confirm it spins up to 6.5k somewhat rapidly, normally change gear at 6k (when having a blast), but then I'm normally looking at the road ahead and the rev counter and not for smoke in the rear view mirror
Chilliman,
An old point of view was that Blue smoke indicates engine wear. If its on lift off overrun then it,s more likely to be valve/guides wear, or on acceleration then its probably worn rings/bores.
Black smoke is over fueling and you should be able to smell it from outside of the car when it is idling.
But I could be totally wrong.
An old point of view was that Blue smoke indicates engine wear. If its on lift off overrun then it,s more likely to be valve/guides wear, or on acceleration then its probably worn rings/bores.
Black smoke is over fueling and you should be able to smell it from outside of the car when it is idling.
But I could be totally wrong.
citizen smith said:
Chilliman,
An old point of view was that Blue smoke indicates engine wear. If its on lift off overrun then it,s more likely to be valve/guides wear, or on acceleration then its probably worn rings/bores.
Black smoke is over fueling and you should be able to smell it from outside of the car when it is idling.
But I could be totally wrong.
I agree, also with valve stem seals you will often get a whiff of smoke when idling, and get that "two stroke" smell.An old point of view was that Blue smoke indicates engine wear. If its on lift off overrun then it,s more likely to be valve/guides wear, or on acceleration then its probably worn rings/bores.
Black smoke is over fueling and you should be able to smell it from outside of the car when it is idling.
But I could be totally wrong.
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