# SAAB 900 running rich

**URL:** <https://community.cartalk.com/t/saab-900-running-rich/33662>\
**Category:** Maintenance/Repairs\
**Tags:** saab, 900\
**Created:** [July 19, 2009, 8:15pm UTC](https://community.cartalk.com/t/saab-900-running-rich/33662 "2009-07-19T20:15:53Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![raleidig](https://avatars.discourse-cdn.com/v4/letter/r/a183cd/32.png) [@raleidig](https://community.cartalk.com/u/raleidig)\
**Post date:** [July 19, 2009, 8:15pm UTC](https://community.cartalk.com/t/saab-900-running-rich/33662/1 "2009-07-19T20:15:53Z")

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My 1991 SAAB 900 seems to be running extremely rich. I have about 230k miles on the car. No fault codes have been set. Black smoke from the exhaust pipe. Will not run abaove 3k rpm. I have just ordered a fuel pressure regulator but inspection of the one I removed does not indicate that it has failed. Any ideas?

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**Author:** ![ok4450](https://avatars.discourse-cdn.com/v4/letter/o/e9bcb4/32.png) [@ok4450](https://community.cartalk.com/u/ok4450)\
**Post date:** [July 19, 2009, 10:49pm UTC](https://community.cartalk.com/t/saab-900-running-rich/33662/2 "2009-07-19T22:49:04Z")

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Some possibilities could be seriously retarded ignition timing, plugged fuel return line to the fuel tank, or a clogged catalytic converter although I’m kind of leaning towards the latter.

This could be checked with a vacuum gauge and if you do a lot of your own service work buying a vac. gauge is highly recommended. It’s one of the most valuable and helpful tools you can own; and they’re cheap too.