DIY_EFI Digest V4 #576

[Espen Hilde]

  Thanks Stuart for a interesting summary.
Yamahas new (High pressure direct injection) HPDI 200hp is better than the 
75% reduction in certain emissions the Environmental protection agency
requires by 2006.
It has a new engine block with longer stroke and 76-degree v 6.
They want to make the engine slimmer to not get into trubbles with the 
boat manufacturers.
To reduce the fuel to a fine mist the system uses high pressure, 
700psi , ficht uses (OMC) 300-400psi , DFI (Merc) 80 psi.
The pressure is developed through a very small high speed pump.
Two stainless steel fuel rails for each cyl row.
The Injectors looks very simular to car efi injectors.......
They say that the high pressure is a part of the whole picture, without 
the high pressure they could not use internal opening style injectors, the
pressure keeps them closed when they need to be closed.
Internal opening style injectors that dont protrude into the combustion
chamber are,unique to the HPDI system. They clame that the most notable
advantage is that they dont impede or disrupt the fuel flume.
Like diesel style injectors vs. efi injectors.
Yamaha uses the common sensors , crank position sensor.TPS,KNOK,
rpm sensor, water temp, air temp,MAP,O2.....o2.............?(patented 02
sensors )
All manufacturers of theese dfi outboard engines has had some bugs
that develop.....
A lake in US has abandoned all engines that are not to the latest
eviromental standards......If you want to take your boat with your old
twostroke engine  out , you have to change your engine to a new one
first.
Mercury delivers a high perf 200 dfi that took 2 place at paris ruoen 24
hour (river) race.The ability to run lean  burn  conditions is great for
reliability as  I see it.

I have 2  2.5efi high performance engines that I am reparing, line boring
new crank, one piston 70grams to heavy +++
They have analog efi with old d-jetronic peek and hold injectors.(As
standard)
The new 2.5 efis has digital boxes ,Motorolabased.
  Any who has any info on them?(GM?)
I hope to put another efi system om my engines and run LPG.......
Liquid injecting.
Any input is appreciated.
To afford to use it.......
Espen Hilde