Has anyone had the subject problem? Engine momentarily stumbles, CEL comes on, engine smoothes out, CEL goes off. Reading stored PCM fault codes by jumpering "TEN" and "GND" terminals in the Diagnostic Connector, turning ignition switch to ON and looking at the CEL shows about 3 seconds of CEL lit, then it goes off. On a 1990 Miata, this means that a) the ECU is operating correctly, and b) there are no stored fault codes.

I always thought that if the CEL came on, even briefly, the fault was stored until the next time the battery was disconnected. Is that incorrect for the RX-7? Never saw this behavior in 18-1/2 years with my Miata.

Thanks for enlightening me!