Date: Mon, 6 Apr 2009 20:02:15 -0700
Reply-To: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject: Re: digifant injection
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re
"Others as well, I think; I think it's only recently that
> they've started doing sequential injection."
Subaru has sequential fuel injection starting in 1990, with
The EJ22 Lecagy engine. ( and they moved beyond the crude Air Flow Meter
then too - to the the much more evovled Air Mass Meter .
Honda right in there too somewhere around that time. - going to sequential.
there's no major significant changse in the fuel injection system in
vanagons from 1983 on .,,,,depending on what you call 'major.'
The Digiget and the later Digifant .........
nothing about those two systems is fundamentally different from each other
............and,
sure the Difigant has the ingniter incorporated into the ECU, aloneg with
electronic control of the ignition timing curve ....
and the Digifant oxygens sensor is heated ...........
oh ........ok, electronic control of idle speed in the Digifant .
but other than those differences, which aren't that big a
differnce..........I don't see any 'real' steps forward in Vangagon fuel
injection from 1983 to 1991. Not in the fundamental principles anyway.
Wouldn't have been very hard for VW to put on a sequential system either.
I think they just saw the end of the vanagon body and chassis in terms of
crash standards and aerodynamics, and decided to just keep making 'em that
way until the end , fuel system wise that is.
It would have been outrageous for VW to make a belt driven overhead
cam head design with 4 valves per cylinder, and knock sensor igntion and
sequential fuel injection, for the last few years of the waterboxer engine.
Not even that hard for a factory to do. Heck........they did it with
their 1.8 inline four gas engine .............1987 Jetta, .......optional
engine is DOHC and 16 valves per cylinder. I just got one to put in a
vanagon. They could have done that for the waterboxer without extreme
expense if they wanted to. Shoot, they could have gotten great ideas from
Subaru in the late 90's for inspiration.
Scott
www.turbovans.com
----- Original Message -----
From: "David Beierl" <dbeierl@ATTGLOBAL.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Monday, April 06, 2009 6:20 PM
Subject: Re: digifant injection
> At 10:50 PM 4/6/2009, Allan Streib wrote:
>> From what I read it seems that all 4 injectors fire together, which
>>confuses me -- I would have guessed that each injector fired just as the
>>intake stroke was starting for that cylinder. Does the fuel vapor just
>>sort of accumulate behind the intake valve until the intake stroke for
>>that cylinder? Surely 3/4 of the injection cycles are not "wasted"
>>fuel??
>
> Digifant and Digijet both, as well as L-Jetronic which the Digis are
> related to. Others as well, I think; I think it's only recently that
> they've started doing sequential injection.
>
>
> --
> David Beierl - Providence RI USA -- http://pws.prserv.net/synergy/Vanagon/
> '89 Po' White Star "Scamp"
| 
