[Diy_efi] Motronic hacking...

Mon Feb 27 22:25:10 UTC 2006

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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>>>
>>>
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>>
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> 
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