ok, I have a 99 civic hatchback and I recently swap in a motor(b-series) with an engine harness from a 97 civic hatch with an obd2 to obd1 jumper harness, I basically just swapped motor over. My question is there a difference on the green interior harness plug near the ecu( i believe it may b called the "A plug" not the little diagnostic one) from the 96-98 to the 99-00 civic when connecting it to the engine harness??? ......... can this be causing my speedometer/odometer(checked vss and seems fine , vtec works, worked in my 97 hatch,gauge cluster worked fine in 97 hatch,fuse is good ) fuel pump not working(it has power , relay is good , had to wire it straight to battery)??? do i need to replace the jumper harness from an 96-98 obd2-obd1 to a 99-00 obd2-obd1 jumper harness since i now owned a 99 model ek? thanks for your time and any help will b greatly appreciated!!!

 

what yr is the ecu i believe the 00-01 acura integra ecus have immobilzers in them and i believe something to do with the fuel pump also.

 

Yes.

I can tell you with absolute certainty that you will have those problems with that setup.

You need to use a '99 - '00 Engine harness and then an OBD2B to OBD1 adapter harness if using an OBD1 ECU.