1990 civic si. OBD1 engine.

I recently converted to OBD1, injectors, dizzy, ecu, etc. When adjusting the timing I've noticed when jumping the blue under-dash service connector that I no longer get the CEL on my dash. Am I missing something here?

With the RyWire harness there are two wires, blue and orange, if i remember correctly, which are used to get codes using the dash CEL.

 

you could wire those two wires to the jumper if you wanted to, or you could do like many of the instructions suggest on those harnesses and put a switch on those two wires on the jumper harness.

 

It's actually going to be one wire.
The other wire is a ground.
Weird that your jumper harness didn't route the one wire to the blue connector.

D4 is the OBD1 pin that you ground for this.

 

Your jumper harness should connect to the wire that goes to the blue connector. I believe the CEL goes out if you don't have any codes, so that 's normal. As long as the light comes on when you first turn the key, it's ok.

 

Sorry, I'm not being clear.

Ya know when you adjust your timing and you jump the blue connector so the ecu doesn't counter your adjustments? Well, as I recall before I went OBD1, when I jumped the service connector the CEL would come on. I would then adjust my timing, turn off the car, pull the jumper, disconnect the battery, reconnect the battery and then all was set.

Now, now that I'm OBD1, when I go to set my timing and jump the service connector, the CEL does not come on, which leads me to believe that I'm not actually adjusting my timing. Is that clear?

What I'm wondering is if now when I need to adjust my timing I just connect the two wires, blue and orange I believe, which are part of the RyWire harness. Is that clear?

 

i have a 89 si hatch did swap of 92 vtech d1600 did ecu swap obd1 cant get vtech to work

 

 

Where do the two wires, blue and orange, trace back to?
If one is ground and the other is going to D4, then you would tie them together.

Whatever you do, you should be able to look at a timing light and see if the ECU is correcting timing while you rotate the distributor.

 

Just connect the orange and blue wires together. Or if you want splice the wire coming off obd1 ecu plugs d4 to your factory b20 (obd0 ecu plug)

 

my harness came with a wire that I ground in order to read ECU codes.

That same wire is the one you'd normally use a jumper on. Just ground it to set your timing. It should say in your instructions specifically which wire. I've just always known it as "the yellow wire."