VW Bosch injection

[Stephen Lamb]

>>That is not true. Early VW fuel inj was "D" Jetronic which was  speed
>>density. Was installed first if I remember correct on mid 60's VW
>>hatchback aircooled engines.
>
>>Frank
>
>Frank Parker may be right about the earliert "D" Jetronic '60 VW air cooled
>engine... I honestly haven't worked on one, and have never seen one. Most of
>my experience in VW's is limited to Beetles and Buses.  It sure sounds
>interesting, though!  The earliest VW with EFI  *I* have seen is a '76 Super
>Beetle with CIS.  I'm sure that the bus engine in question would be CIS,
>however, since it was also a late 70's model.

Perhaps I'm getting my acronyms confused here, but isn't CIS really just a
sort of 'sophisticated' mechanical injection system ?? - ie not
'electronic' (EFI) at all ?? (I'm new to this group, so forgive my
ignorance).

My understanding is that D-Jetronic was the first true production EFI
system and was used over here in such cars as the Volvo 164E.  It differed
from the later L-Jetronic system in a number of significant ways:

1. A 'MAP' sensor was used to determine engine load.
2. A separate pair of mechanical 'points' installed in the distributor were
used to trigger the injectors
3. The injectors were fired in groups.  In the case of the 6 cylinder 164E
this was in two groups of 3.
4. The TPS was designed to sense throttle 'rate' as well as idle and WOT.
5.  The injectors delivered the full amount required by each cylinder in
one 'hit' as opposed the the L-Jetronic system where the amount is
delivered in two 'lots'.  This also meant that the injectors for the
D-Jetronic system were designed for a higher flow rate.

I know a bit about the D-Jetronic system as a couple of years ago I adapted
it to run on a Nissan Skyline (2.8L, 6-cylinder).  It didn't work very
well, but I didn't have the time to sort out the bugs and it got shelved.

Stephen Lamb
Dept. of Defence DSTO, AMRL
506 Lorimer Street
Fishermans Bend  VIC  3207 Australia
Tel: +61 3 9626 7525
Fax: +61 3 9626 7089

IZCC #180