I have an ECM that has a DTC 61, secondary vacuum fault code. It is an internal issue. It does let the car idle fine, it just restricts the driving rpm to 3k. I'll ship it to you as I think it would be okay as a test swap @ idle if you think it would help?
The ECM is the original one from my 90 btw. I just don't have a EPROM to put in it.
A noid light would do the same thing though.
Tom