[Diy_efi] Motronic hacking...

Tue Feb 28 00:16:06 UTC 2006

Thanks, Torbjorn.  I have replaced the air boot, all hoses, o-rings, that I
could find.  Car ran well before I tweaked the air flap adjustment while
trying to set idle mixture (the normal idle screw made no change - because,
as I learned, the throttle-plate wiring connection had not been fully
seated, and was disconnected.   Turbo intercooler tests have not been made,
but no cause to suspect failure there, since the car ran fine before I
messed with the air flap screw (CO adjustment, according to the book) and
throttle plate (re-soldering some fractured internal solder joints, in the
switch).  This engine has double knock sensors and one O2 sensor on the
header pipe visible by the passenger-side fenderwell.  The Bentley manual
gives a method for basic setting of this air flap, but it requires removal
of air boot, which was a hassle to install, so I'm hoping there's a "tune by
ear" or "set by feel"  or "bottom the screw and count turns"  method?
Maybe I'm just fooling myself to think this is possible, and simply need to
take the boot off and do it by the book?

Ernest

----- Original Message -----
From: "Torbj?rn Forsman" <torbjorn.forsman at gengas.nu>
To: <diy_efi at diy-efi.org>
Sent: Monday, February 27, 2006 2:25 PM
Subject: Re: [Diy_efi] Motronic hacking...

> I think a such Audi probably would have K-lambda or KE-jetronic?
> A common cause for difficult starting of those engines is if there is an
> air leak somewhere after the air flow meter. On a turbo engine, a
> leaking intercooler often causes this problem. Cracked rubber parts
> (hoses etc) are also commonly found.
>
> Best regards
>
> Torbj?rn Forsman
>
> Ernest Buckler wrote:
> > 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
> >>>>
> >>>>_______________________________________________
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> >>>>Diy_efi at diy-efi.org
> >>>>http://lists.diy-efi.org/mailman/listinfo/diy_efi
> >>>>
> >>>
> >>>
> >>>_______________________________________________
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> >>>
> >>
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