Cold start problem

Hi Kurt,

Norbert has linked to the correct ECU. Just buy that one. If I find my Volvo ECUs (which I have not on first sight), it will be too costly with shipping and currency exchange. So I will only search again if I find my ECU.

Hello,

I have sourced several correct ECU # 0 280 000 017. One from Ebay and one from a local source.

Any advise on what to look for or what should be tested to be sure the replacement ECU is in good working order. Is there a way to test the internal MAP sensor?

It appears the Bosch Classic repair service is not available for the North America market. This is from the Bosch Electronic Service website:

Dear customers,

due to the “Brexit” we are only able to process orders and new registrations from customers from UK and Northern Ireland if you enter a valid EORI number.
The EORI number (only valid for GB) will start with ‘GB’ followed by 12 numbers, for example GB123456789012.

If you have any questions, please contact our customer hotline (tel: +49 (0)5121 49 5720)

Your Bosch Electronic Service Team

Thanks,
Kurt

Hi Kurt,

well just install and test it. Normally a Bosch Service should locally hande your service request and forward to Bosch Classic in Germany. That should work. But yes Brexit has unnecessarily complicated life. Even if I wanted I ould not be able to offer help as I would not be able to import and export an ECU with all customs formalities. So I undestand those difficulties.

On MAP sensor you can do resistance, ground and vacuum leakage test. If it is from 70s (date stamp on rivet upper right or on housing back) x2x or x3x it should be trustable. But of course the devil lies in the details.

I now have a correct ECU and the cold-start problem is mostly resolved.

At temperatures above 4 degrees Celsius (40 degrees Fahrenheit) the engine will crank and run and warm up normally. Below this, it will crank, run, and then stall. After 2-3 more key cycles it will stay running but rough and then begin to smooth and run.

During the colder starts, and once it does stay running, the idle will now surge until it gets a bit warmer. This is a new condition with this ECU. Before, the cold idle was always high until the engine warmed up and then the idle would drop to normal. A bit erratic, but functional.

I think I have a faulty Auxiliary Air Valve and now with the correct ECU installed, I am seeing the over-run function working. Does that sound like a correct assumption?

Did the re-manufactured ECU that was installed have the over-run function? Please reference the beginning post for that ECU number.

What are my options for the Auxiliary Air Valve if it is needed?

Thanks again,
Kurt

Hi Kurt,

its all in my compendium

List of ECUs also contains their features.

Thanks. Found it and also realized this information was given earlier in this thread.