[Diy_efi] Motronic hacking...

Mon Feb 27 00:44:15 UTC 2006

Torbjorn,
Many thanks for the details info.  Available nowhere else in such concise
and accurate form.  Superb reference info.

I'm working on a 1989 Audi 2.2L turbo, slowly figuring it out.  Right now I
have the CO adjustment so far out that after the cold start stops, the car
dies and will not restart.  But before I  changed this adjustment in error,
the car ran fine, so I know the basics are there, I just have to figure out
how to get a basic setting again, so I can drive to the shop where the
'sniffer' is.

Ernest Buckler
Spokane, WA, USA

----- Original Message -----
From: "Torbj?rn Forsman" <torbjorn.forsman at gengas.nu>
To: <diy_efi at diy-efi.org>
Sent: Sunday, February 26, 2006 2:55 PM
Subject: Re: [Diy_efi] Motronic hacking...

> It is not very precise to call an injection system "Jetronic". This is a
> brand name that Bosch uses for all systems that only deal with fuel
> injection, not ignition.
>
> Analog systems are D-jetronic (manufactured from about 1969 to 1974),
> L-jetronic (1974 to mid-80's), most LE-jetronic (1981 to early 90's) and
> all LU-jetronic (the same as LE but with closed-loop lambda control).
>
> Digital systems are LH-jetronic (from early 80's to mid 90's, most of
> them but not all have closed-loop, LH 2.4 and later have adaptive lambda
> correction and some diagnostic features), LE3-jetronic (the last
> non-closed loop system, the ecu is integrated in the air flow meter)
> and Mono-jetronic (a TBI system, only used with closed-loop and adaptive
> lambda correction).
>
> The K-jetronic, an all-mechanical system should also be mentioned. It
> may have a closed-loop add-on and is then called K-lambda-jetronic. A
> similar but newer variant is called KE-jetronic, it exists both without
> and with closed-loop. Most KE systems are analog but the KE3 is digital
> (and then uses an ecu that is very similar to the Mono-jetronic ecu).
>
> Most digital Jetronic systems use an Intel MCS-51 CPU. Either a standard
>   8051/8031 with a separate A/D converter, or an 80535/80C535. In some
> cases, mask programmed 8051's may be found but they more commonly have
> an external eprom. Anyway, all PCBs are designed for external eprom so
> it is a simple task to solder an eprom socket and the address latch in
> place, and change the jumper for the CPU's EA signal.
> The eprom may be socketed or soldered in place depending on requirements
> from each car manufacturer.
>
> Some older LH-jetronic (in particular, LH 2.2) use instead an 8049 CPU.
> The very earliest LH systems might have an RCA 1802, like the early
> Motronic systems.
>
> The simplest way to identify a Jetronic system is to look at the Bosch
> part number of the ECU.
> I.e. 0 280 000 561. The first six digits tell just that it is a Jetronic
> CPU. The seventh digit indicates the number of cylinders, 0 means 4
> cylinders, 1 means 6 cylinders and 2 means 8 cylinders. The eighth digit
> indicates the variant. 0 means D-jetronic, 1 and 2 means L-jetronic, 3
> means LE- and LU-jetronic, 5 and 9 means LH-jetronic, 7 means
> Mono-jetronic and 8 means K-lambda and KE. The two last digits are a
> leap number.
>
> So, when asking about a "Jetronic" system, be sure to include the
> variant of the system. I.e. mention that you have an LH 2.4 with
> closed-loop.
>
> Best regards
>
> Torbj?rn Forsman
>
>
> David Allen wrote:
> > Some of the Jetronic were (gasp) analog....
> > David
> >
> >
> > ----- Original Message -----
> > From: "Mike" <mlschmidt at sprintmail.com>
> > To: <diy_efi at diy-efi.org>
> > Sent: Friday, February 24, 2006 10:14 AM
> > Subject: [Diy_efi] Motronic hacking...
> >
> >
> >
> >>Anyone know of any of this sort of stuff available for the Jetronic
> >
> > system?
> >
> >>Mike
> >>
> >>_______________________________________________
> >>Diy_efi mailing list
> >>Diy_efi at diy-efi.org
> >>http://lists.diy-efi.org/mailman/listinfo/diy_efi
> >>
> >
> >
> > _______________________________________________
> > Diy_efi mailing list
> > Diy_efi at diy-efi.org
> > http://lists.diy-efi.org/mailman/listinfo/diy_efi
> >
>
> _______________________________________________
> Diy_efi mailing list
> Diy_efi at diy-efi.org
> http://lists.diy-efi.org/mailman/listinfo/diy_efi
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.1.375 / Virus Database: 268.1.0/269 - Release Date: 2/24/2006
>
>