Puff of smoke on start - page 1 - Troubleshooting - VWDiesel.net The IDI, TDI, and mTDI source.

• Puff of smoke on start by DAKOTAKIDD on 04 Sep, 2009 18:44
• Hey guys,  I did search on this topic and could not find an exact answer but I have a 91 eco diesel jetta 1.6 turbo and on start I am getting a small puff of brown/black/grey smoke out the back.  My wife told me what colors were but I have not seen it for my self.
  
  Is this anything to be concerned with?
  
  Thx
  
  DK
• #1 by burn_your_money on 04 Sep, 2009 19:28
• It's normal for the older pumps. They do it by design. Starting with the AAZ pump bosch put in a limiter to reduce the starting fuel, which in return lowered the puff of smoke.
• #2 by Baron VonZeppelin on 04 Sep, 2009 22:32
• The next time you can do your general maintenance all at one time, or at least the oil change and air filter at same, it might clear up or minimize for a while. If luck is in your favor.
  
  I don't get too overwhelmed by anything mine does on a restart.
  It does its own thing from time to time. Most the times seems clean, sometimes a little blue sometimes a little black sometimes little greyish.
  First crank of the day is when most of its colored farts are done.
  
  But always runs the same/fine.
• #3 by Zulfiqar on 09 Sep, 2009 22:33
• thats normal
  
  when the pump is shut off and not spinning, the fuelling goes to max position - as soon as the engine fires and the pump reaches 300 or 400 revs the centifugal weights get pulled and it idles
  
  The black is from the huge amount of fuel for startup
• #4 by LoneWolf on 10 Sep, 2009 15:15
• a slight blue tinge is sometimes present due to oil sitting on the piston/ rings just from the normal lube process, mines a smokey little bugger in a morning lol
• #5 by Zulfiqar on 11 Sep, 2009 04:55
• yeah - and better check your air filter - if clogged the engine will siphon oil and mist it in the precup - it'll burn blue on startup then
• #6 by DAKOTAKIDD on 11 Sep, 2009 07:17
• Thanks for all the reply's!!  After reading them all it seems I am worrying about nothing.  I have checked my air filter and its wet from rain ingestion.  I will dry it out and see if it changes anything.
  
  Cheers!!
• #7 by maxfax on 11 Sep, 2009 07:19
• Rain ingestion!?!?     After you get your filtered dried out you may want to get that issue sorted as well...
• #8 by DAKOTAKIDD on 11 Sep, 2009 08:33
• I have looked at the air box and it has two intakes.  One in the front ( ram air) and one that has a "snorkel" that leads to the rear of the engine.  The rear inlet leads to a flapper valve in the air box.  I have no idea what its for.
  
  Maybe someone call help here
• #9 by Peter on 11 Sep, 2009 09:43
• Quote from: DAKOTAKIDD on 11 Sep, 2009 07:17

  Thanks for all the reply's!!  After reading them all it seems I am worrying about nothing.  I have checked my air filter and its wet from rain ingestion.  I will dry it out and see if it changes anything.
  
  Cheers!!
  

  that air filter needs to be protected from sucking in to much moisture/rain..go back to the stock set up if useing a stock style filter..I have had good luck with either the mann or mahle filters..this might apply to you; the trouble with many aftermarket filters (fram in my case) ..once they become to wet, the drying process changes the filter material in such a way that it becomes difficult for the diesel to breathe..and diesels need to get all they can get and this happened to my N/A golf...a clean looking fram filter that was slightly choking the motor..could be another possible reason for the smoke (black color that is)..how is the fuel consumption
• #10 by DAKOTAKIDD on 11 Sep, 2009 09:52
• The funny thing about this is that I think its the stock set up for the eco diesel.  I looked at a 89 jetta idi and it has a different set up with only one intake, no flapper valve and the front intake has a boot that connects the piping to the inner fender well.  Mine has no hole or nothing..  Maybe someone with a eco can ding in here to be certain.
• #11 by Baron VonZeppelin on 11 Sep, 2009 16:07
• I have a great shot of a minty 92 ECO underhood.
  IM or post your email addy and I will send it to you.
  i'm unable to post pix to a photohoster
  
  it sounds like your system has been modified.
  maybe even a rendition of a GTD type cold air intake.
  
  A wet air filter sounds AWFUL strange.
• #12 by DAKOTAKIDD on 12 Sep, 2009 06:41
• You have a pm.
• #13 by burn_your_money on 12 Sep, 2009 07:20
• It sounds normal to me. I've never seen an eco diesel but all the air boxes I've seen have that flapper valve for drawing in warm air from the back of the motor on cold starts.
  
  Come to think of it it's been a while since I saw the Mk2 air box and I may be confused with all the mk3 air boxes...
• #14 by rabbitman on 12 Sep, 2009 12:22
• Quote from: DAKOTAKIDD on 11 Sep, 2009 08:33

  I have looked at the air box and it has two intakes.  One in the front ( ram air) and one that has a "snorkel" that leads to the rear of the engine.  The rear inlet leads to a flapper valve in the air box.  I have no idea what its for.
  
  Maybe someone call help here
  

  
  My '84 carbureted gasser rabbit's airbox sounds just like that, the back intake was for heated air off the exhaust mani and the flapper chooses were the air comes from.
  
  Maybe the PO of your car was like me, my gassers airbox is now in the diesel