89 four door with 91 si single cam, check light comes on and when i turn the key over to acc. and watch the ecu it blinks 17 SHORT flashes with no long pauses, any ideas? a code 17 is vss from all i can find well it has mechanical speedo run thro a cable duh! so whats the problem it backfires a little some days the light comes on others it does not. anyone ever had this problem?

 

The cluster could be messed up. I kno the cable from the tranny goes to the back of the cluster like you said but the cluster then converts the mechanical signle to a electronic single. That the ecu can read Via a wire going from the cluster to the ecu. I'm not to sure of the wire color or the pin number for the wire on the back of the cluster. Maybe some one else can help out you out more...

 

Mine does the same thing. I've been told that obd0 has all short flashes and obd1 is a mixture of long and short. I could be wrong but every code that I got was good and was fixed.