Citroen SM injector points

Hi Norbert,

The updated SM pin-out list seems fine - with the exception of pin 9 (still shows 12, rather than 11).

It is always frustrating to find faults in factory technical documentation. The SM wiring diagram omits to illustrate a critical earth - this same error is contained in the "Kundendienst-Anleitung" D-jet manual on the DS & SM I sourced from Partsbob at Bosch.

My mind turned to the injectors yesterday too. They are genuine Bosch 0 280 150 043 (photo attached). Should be ok.

If the pain in my back from yesterdays SM work subsides, I'll get the readings that Volker recommends later today.

Cheers,
Rhys

Hi Rhys,
thank you for your correction. I will correct my error.

One more question: Is the colour-coding of the wires correct? We found out before the wires aren't coloured at DS21/23 as being noticed in the Bosch instruction.

Regards
Norbert

Hi fellas,

Norbert: The wires at the back of the ECU block are all black. Each wire has a tiny white adhesive tag with its corresponding ID number.

Volker: The spread sheet with resistance values you requested are attached, If I have misinterpreted requirements, identify the deficiency and I'll get the required information.

The injectors location on the Maserati engine are buried beneath the plenum castings, so fitting the connectors requires ones hand to be mutated somewhere between an octopus tentacle - and a monkeys claw. Some of the connectors seemed to only just be engaged so I measured the pin-outs 3 -6 again.

Regards,
Rhys

Hi Rhys,

that looks better then before. All injectors have correct resistance, cables to ground and from ECU are okay. We have a bit variance like 0.5 Ohm, but the rest fits and I contribute it to measuring tolerances.

Hi Volker,

So....am I left with what is likely a faulty ECU?

Cheers,
Rhys

Hi Rhys,

after you have measured all sensors at ECU connector and those values were correct, then there is only two more things to check:

1. Close the fuel hose to the cold start valve.
2. There is a second throttle switch on Citroen SM.That had nothing to do with D-Jetronic but it somehow involved. I will have to read that function again.

If both are correct, ignition is verified, then indeed we are down to MAP sensor and ECU. As your MAP sensor is of type 1, with rivets and still originally potted, it can hardly be mistuned. What was repaired on your ECU and how was it tested afterwards?