[Vwdiesel] Injector pressure setting -- ( by Hagar Feel )

LBaird119 at aol.com LBaird119 at aol.com
Sat Dec 6 01:50:20 EST 2003

  The "playing" I've done with injectors has left me more than disappointed 
with most of the results short of using a new nozzle.  Probably 80% of the 
time, I end up with as bad or worse of a pattern trying to get a used nozzle 
to clean up and shoot better.  I've never done any playing with the pressures 

to be honest, but I strongly believe that the higher the compression, the 
higher the break pressure needs to be to maintain the "same" injection 
characteristics.  This would take into consideration combustion pressure 
as well, not just static compression.  Call it observations from engine's  
break in performance when the compression was too high.  ;-)
  You can't check the pattern without a tester, or rigging the injectors 
to a pump and turning it.  A bad pattern can really affect mileage and 
smooth running.  It doesn't seem to affect power as much as other 
things but it still does some.
  I can see where lower pressure would aid an ailing pump however the 
pumps are capable of much higher pressures than they are running at.  
Even so, lowering injection pressure, to help a worn pump is like putting 
smaller jets in your carb to compensate for the oil the engine's burning. 
Sure it helps, but it's a band-aid way of "fixing" a problem.  Almost more 
work than it's worth.  In the long run it certainly is, especially if you 
to keep the vehicle rather than turn it for some quick cash.
  I used to do a LOT on the cheap.  I'm still cheap but I weigh my time 
into the equation much more heavily now.  A $400 pump rebuild, that'll 
need done down the road anyway, is much handier than resetting all 
the injectors until it fails, then replace and do it again and so on.  I've 
come to value dependability and not needing to work on the car every 
other weekend.  :)  I wouldn't mind driving that 914 again though!  (My 
Saturday afternoon-every-other-weekend-car.)  :)

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