I know you are supposed to jump the ignition timing to time a 90 civic hb d15b in order to set timing.In my hb the ignition timing jumper is not under hood on left side near shock tower. one book said it would be under the passenger side near the glove compartment. I found a blue two pin jumper with green and brown wires so I jumped it and it did not set a check engine light. On the posts that i have found when you jump the jumper its supposed to set a check engine light? If it doesent set a check engine light is it really bypassing the ecu?? my engine is having bad detionation problems and I'm not sure it is properly set.

 

Yes that is the correct jumper. No it will not set out a code. At least, mine did not.