[Vwdiesel] Uphill overheat update - new parts - now black smoke

LBaird119 at aol.com LBaird119 at aol.com
Mon Jul 9 16:03:30 EDT 2007

In a message dated 7/9/2007 12:38:55 PM Pacific Daylight Time, 
william at taygan.com writes:

> Is timing to cam or to flywheel for the rattle when the cold start lever
> is pulled out?  Since mine rattles pulled out and is smooth pushed in.
> How about black smoke, cam or flywheel?

  Well, timing is to the crank (for the pump).  Cam timing must be close 
regardless or the valves hit the piston.  Timing sounds to be really close 
since you get the noisier with the knob out and smooth with it in.  
  Black smoke is an unburned fuel issue or more correctly incompletely 
burned fuel.  Unburned tends more to be white.  It's an injected quantity 
moreso than a timing issue. 

> Summary: 
> Lots of black smoke on uphills and still overheating, pulled turbo line
> to aneroid an much of the smoke and overheating goes away, but still
> black smoke on start and opacity visible in the sunlight, still some
> heating on the long uphills.

  You'll almost always see the smoke through sunlight or headlights 
behind you at night.  Lots of black smoke, overheating on hills 
definitely indicates overfueling and most would first turn down 
the pump.  Not so fast.  Poor injectors will also create black 
smoke, hotter temps, poor mileage, white smoke at startup, 
excessive knocking or rattling and so on.  
  Dirty air filter can do what you're seeing also as can a restrictive 
exhaust.  In other words, unless you know or strongly suspect 
someone's been dinking with the fueling of the pump, be sure 
all other likely causes are correct or fixed before dinking with 
it yourself!

> I think I need to confirm TDC, solid core solder through #4 glow hole
> the best non-invasive way? I have a lot of bad luck and am a bit nervous
> about doing this.

  It runs.  TDC is darn close then.  Mark on the flywheel will be 
more accurate than a piece of metal through an injector hole.  
If the flywheel were on wrong and the mark's nowhere to be 
found at TDC THEN you start trying to find where it really is. 
If you have a mark, time to it, be done.

> Compression even, all between 415-425. Would this mean the cam/TDC/ip is
> correct?

  If the cam were wrong, you'd hear clacking or one clunk and it 
wouldn't turn over anymore.  Compression will be what it is by 
the condition of the valves, rings and valve lash.  If the cam timing 
were off THAT far, the piston would hit the valves.
  Overall it doesn't sound like a timing issue at all.  First place I'd 
look at breathing then injectors.  If all is well there then back out 
the fuel delivery screw a tad at a time until it comes clean.  Here's 
one place a pyrometer helps some with diagnosis.

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