Bosch Motronic ECU Repairs

[bteoh]

Does anyone in Australia, preferably Perth repair Bosch Motronic ECU's. I have a couple of bosch 0261200117 from an Alfa 164 3.0 V6 that needs repairs. One seems to make the car run very rough and the other may have had a power spike. It runs ok but after a few minutes, it causes the engine to shut down.
Thanks for any help.

[bazzbazz]

Try Antionios Auto service, if can't he should know who can.

https://www.antoniosautoservice.com.au/

[festy]

It runs ok but after a few minutes, it causes the engine to shut down.

Does the engine then re-start ok, but shuts down again after another few minutes?

[bteoh]

Hi festy,
Yeah, after that it starts ok. Then after a few mins, it dies again. Sometimes it won't start up again until left for a while. I managed to get a new ECU 0261200117 from Taiwan. Not sure if the faulty one can be repaired in Oz?
Cheers

[festy]

Sounds like it could possibly be the fuel pump driver circuit?
Around 10 years ago I repaired one of these for MD that had the same sort of symptoms.

If its the S450 custom Bosch driver chip that's faulty then you'd have to get a replacement from a donor Motronic ECU, but I've never seen one of those fail (yet).
But seeing as it runs for a short while after a start then my guess would be capacitor C470 - which is easy to test and replace, and IIRC was the problem in MD's ECU.

You should be able to test to see if its the fuel pump driver or not by hooking a small light up between the ECU fuel pump output (pin 20) and +12v.
The lamp should come on as soon as the engine starts, but if it starts to flicker and turn off before the engine dies then that would confirm where the problem was.
(if the fuel pump driver is working properly, the lamp will switch off immediately *after* the engine stops, without flickering).

   

[bteoh]

Thanks Festy, will try that out. Is there a simple way to hook up a wire to pin 20. I know the wires to the ecu connector is hidden behind a rubber sheath, so will have to remove that first.
Cheers 

[festy]

You don't actually need to check right at pin 20, anywhere you can monitor the power going to the fuel pump will do.
I don't know much at all about 164s, but google suggests that the fuel pump relay is behind the passenger side headlight, that might be a good spot to check from.

The ECU grounds pin 20 to activate the fuel pump, so one side of the fuel pump relay's coil will be switched 12v with ignition and the other side will be grounded while the engine is running.

If the relay is accessible and you know that the engine will reliably cut out a short time after starting, you might even be able to just hold your hand on the relay and wait while the engine is idling.
You can usually feel the 'click' of a relay switching in and out.