'95 960. 41000 miles. (yes,41). Owned it for 5 years and this is the first time anything mechanical has come up beside a bad Schrader valve in the AC.
It started missing a week or so ago. Saab tech friend checked out the following: Identified problem coming from #3 cylinder, switched plug, no difference; switched coil-no diff; switched injector- same. Ran a can of GM combustion chamber cleaner through--no diff. Took compression test. All cylinders between 220# and 227. Checked injector with a test lamp. Firing OK. Vaccum gauge test shows steady 20 lbs. Replaced all plugs with new. Old ones looked textbook perfect, but it was worth a try.
Starting in cool AM, runs perfect. After warmup, miss comes back. Incremental increase in RPM when AC comes on will eliminate miss.
At regular street driving miss disappears or is imperceptible. At highway speeds it runs perfectly with much power.
Check engine light just came on about a half hour ago.
Sure could use some good advice. Jim