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Start-up Exhaust Soot

Started by raueda1, 03 September 2022, 04:40 PM

raueda1

Per my recent K-Jet troubles thread, a new question arises.  During these problems the car was driven around with very wrong mixture conditions - at times almost certainly lean and way too rich at others.  it now seems to be well sorted out.  However, this morning I noticed that after a cold start the exhaust sprayed out some soot along with the water drops often accompanying a cold start.  See pic of garage floor under exhaust.  The car got relatively cool overnight, enough for water droplets to form.  I hadn't noticed this before, but at my house it has recently been to warm for this to happen. In any case, the exhaust seems clean, no obvious soot.  FWIW, I set the mixture by "feel," not using a meter.  Not ideal perhaps, but I'm comfortable with it.  The smooth-idle-sweet-spot is very specific and obvious.

Anyway, all this leads me to wonder....   Does blowing out soot necessarily indicate a rich running condition right now?  Or might I be blowing out soot accumulated from the time driving when it was way too rich?  And if so, how long might it take to effectively blow it out?  I have put about 50 miles on the car since it was fixed, not all that much.  I can imagine that it takes some time to really clear the exhaust system.  Assuming that it's really OK, I'm planning a road trip that would blow out the pipes - ~1500 miles of high speed, high temp desert driving.  Comments welcome as always and cheers,
-Dave
Now:  1976 6.9 Euro, 2015 GL550
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

Randys01

Perfectly normal. The road trip  will do wonders.

raueda1

Quote from: Randys01 on 04 September 2022, 03:27 AMPerfectly normal. The road trip  will do wonders.
Music to my ears, just what I hoped for.  Thanks. 

As an aside, I've noticed that after an operating disruption such I just had, that it often seems to take a little while to get the car "restabilized."  That is, the idle or mixture can be fine but then go a little out of whack so it needs re-tweaking.  Usually a couple times.  Then it settles down and runs fine until the next thing goes wrong.  Maybe it's just an old car thing.  At least in this case it's never nearly as bad as it was on old carbureted cars I had.  Cheers!
-Dave
Now:  1976 6.9 Euro, 2015 GL550
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0