[alex-84]

hello,
sorry if i make some mistakes i don't speak very good english,
my name is alexandre and i come from the south of france.

I plan to make a pnp board to replace old motronic ecu from porsche 911 3.2

the goal will be to replace only the ecu, because most fans of these cars don't like making engine modifications...
if possible no modification on the wiring, the sensors, or the injectors, and that's where it gets complicated

for the ECU connector it is a tyco 35 pin, quite rare but I think I found some in China,

ignition is distributor so just need an igbt,

bosch idle solenoid valve has three wires so two low side drivers will do the job,

there is no tps sensor, just a full throttle and idle switch,
there is no map sensor,
there is just a vane type flow meter which gives a 0-5v signal,
I was thinking of using this signal instead of the tps input, it should just ask for a slightly different setting from the table, but I don't know if it has already been done, or if it's possible with speeduino,

there are two vr sensors, one on a 132 tooth wheel with no missing tooth, and the other has only one tooth for position, the "dual wheel" algorithm should work, but both sensors are on the crankshaft , I don't know if this is a problem,

and my last question relates to the injectors, they are low-z, they are wired 3 by 3 on two outputs of the ecu,
and in the original ecu the two outputs are connected to the same peak and hold circuit, the components of this circuit are bosch references that are not marketed,
I'm not sure how to control these injectors, I found the LM1949 peak and hold circuit, but it seems that one is needed per injector, I don't know if having the injectors connected in common will work...

if someone can bring me information on these points it would be really nice,
I will obviously share the work I do,
thanks!

[alex-84]

here is a view of the original bosch peak and hold driver present in the ecu:



for the vm target, I just realized that 132 is not a multiple of 360, i will have to test the non-360 decoder.

[titiz]

Hello, Alex I am also French,
I invite you to get closer to the designer of the pcb motronic 1.1, 1.2, 1.3 speudo Raku and Pazi designer of the pcb m42 m50 m60 and m52.
They will be able to orient you, For the pinout you can find it simpler, take an old bmw e30 calculator,
I have it in stock, I will just ask you for the shipping costs. Can you also use a standard speeduino and plug it directly into a bosch box?
Good luck with your research and development. And if I can help you, don't hesitate.

[Vauhtivaunu]

I'm not sure how to control these injectors, I found the LM1949 peak and hold circuit, but it seems that one is needed per injector, I don't know if having the injectors connected in common will work...

I´ve repaired one MSPNP2-box and there is LM1949 with large darlington. This was BMW 55-pin box and BMW Motronic uses 3 injectors/channel so it could be possible to use LM1949 in that purpose. There is no schematics since MSPNP2 is commercial product. If one could get MSPNP2 and reverse-engineer injector circuit it could be possible to do this.