[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
plan
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.) :)
Loren
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