[Diy_efi] Motronic hacking...

[Mike]

I should have been more specific. I didn't realize that there were that 
many variations of "Jetronic". The one I was looking for information on is 
what's supposed to be LH-Jetronic 2.3 with closed loop lambda correction 
and some diagnostic code storage capability. The Bosch part number is 0 280 
002 504. The ignition control is "EZK" with knock sensors, and should be 
either Bosch part number 0 227 400 154 or 0 227 400 197.

Mike



At 04:55 PM 02/26/06, you wrote:
>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