ECU failure on a Motronic spiders is not at all common. Some mechanics tend to blame expensive electronics when they feel too lazy to do proper troubleshooting. Unfortunately, the ECU is the most expensive component of the system and the wrong place to start if you want to start swapping parts.
If the proper diaganosis is indeed the ECU, I have a used one from a '91 that should work on your 90 spider.
If the proper diaganosis is indeed the ECU, I have a used one from a '91 that should work on your 90 spider.
