random puffs of blue/dark smoke
 

cars been fine all last year, and up and till this week,
At random the car idleing at a light will just throw out a haze of smoke, not white but dark color, could be fuel could be oil.
car has under 10k on new rebuild with new oilcontrol ring casings and irons with zero stepwear,
i try to premix 120-1, but last time i recall when i filled up, i may have over done it as i couldnt put as much gas in as i though,
now im wondering if there is a chance, that im getting random over oil filled fuel into the engine and causing it to throw a little bit of smoke, or is something else going bad?
86 turbo s4 t04r 550cc pri 1600 sec aem 340lph pump, small streeport

bump anyone?

First thing I'd do is have someone follow you in another car as you drive, just so you can get a more accurate characterization of what it's doing & under what conditions. You might only be noticing smoke at idle, sitting at a light - but you may have smoke under load, decel, etc. while driving too.

Things you'll want to observe:
- On a cold start, does it smoke, what color and what does it smell like?
- Driving along with someone behind you, have them observe & make note of any noticeable smoke (color/smell/how dense is it?) while you do the following after the car is warmed up to operating temp:
- Easy, moderate & hard acceleration conditions, to include full throttle/max boost runs
- Deceleration & throttle lift conditions
- Cruising at a steady speed in gear

Report back on the above, and we can give you a better idea of whats going on.

Don't forget it could be coming from the turbo:

Common Turbo Faults and How to Spot Them | AET Turbos

i did put my car on a hoist and i could see some fuel/oil (premix mixture) seeping from the lim gasket on the rear rotor, i expect my car has some pooling fuel in the intake runners
ie running 10.0 afr at 5psi... i expect, that under 25% throttle my fd throttle body isnt opening any butterflies to the secondarys and the fuel that is being sent there is pooling, and randomly will dribble in or get sucked in when im idleing

update, i tried, staging the secondaries up higher and just driving in vacuum, it seemed to do the trick and now its back, im starting to get really pissed here, it only seems to happen at idle, i had someone follow me, nothing crazy while driving under load accel decel, just idling and its killing me in traffic im starting to really hate driving the damn thing, its very random, doesnt usally happen in the morning (7am) seems to happen alot at (5pm) in bumper to bumper traffic. im at the point im almost calling a rebuild, even tho I JUST DID THAT.

As mentioned might want to rule out the turbo seal before tearing it down...proper drain design,good crank vent etc.

-10an drain to s4 front cover, fitting has a slight weep to it but doesnt look concerning to remove at the moment soon tho as i want to fix that, -4 feed to turbo, its a journal t04r so no need for restrictor, have a -10 line from oil fill cap to a catch can for crank case vent, car has little blow by as catch can barely fills, 3 hour dyno put maybe a tea spoon of mositure in it,

update, it did start to happen after a FD alt install and 340lph fuelpump,
i have my coils mounted near the frame rail, and the fd alt is fairly close to it, idk if theres maybe electrical distortion, messing up my coils? it runs and pulls like normal nothing different there, but maybe its miss firing and cant tell, not sure, going to pull UIM/LIM and check for oil in them and see if i can get a bore scope in the block to see if anything is weird

pete

Things you'll want to observe:
- On a cold start, does it smoke, what color and what does it smell like? light haze more so white ish maybe very small blue
- Driving along with someone behind you, have them observe & make note of any noticeable smoke, while driving he said no smoke, car always smelt like fuel,
) while you do the following after the car is warmed up to operating temp: (zero smoke)
- Easy, moderate & hard acceleration conditions, to include full throttle/max boost runs (zero smoke)
- Deceleration & throttle lift conditions (zero smoke)
- Cruising at a steady speed in gear (zero smoke)

he says the only time it smokes or puffs a small cloud, is after driving and coming to a stop aka a light it puffs then goes away.

pete

Things you'll want to observe:
- On a cold start, does it smoke, what color and what does it smell like? light haze more so white ish maybe very small blue
- Driving along with someone behind you, have them observe & make note of any noticeable smoke, while driving he said no smoke, car always smelt like fuel,
) while you do the following after the car is warmed up to operating temp: (zero smoke)
- Easy, moderate & hard acceleration conditions, to include full throttle/max boost runs (zero smoke)
- Deceleration & throttle lift conditions (zero smoke)
- Cruising at a steady speed in gear (zero smoke)

he says the only time it smokes or puffs a small cloud, is after driving and coming to a stop aka a light it puffs then goes away.