i bought a 2000 civic ex and im piecing it together its not getting spark and the fuel pump is not priming and i want to know if its because it has a 96 ex engine harness on it or any other info would help...

 

'96 - '98 engine harnesses aren't compatible with a '99 - '00 chassis and vice versa. Although IIRC the engine should still run, most of the problems had to do with gauges not functioning.

 

i just found out the engine harness is out of a 99 the engine harness has 4 plugs that go into the ecu but the ecu only has 3 spots so i have a green one left over but i dont know where is does any help ppl

 

Extra connector = Automatic transmission harness?

No start problem:
Are important ground wires on the thermostat housing and transmission connected?

 

I heard that the difference is the 99 (obd2b) doesn't have the green plug. It has all the connectors going into the ECU whereas the 96-98 has the 3 for the ECU and the green plug is off to the side. I'm pretty sure some of the wires go to different pins as well. Just get yourself the right harness.

 

99-00 harness has 2 ecu plugs on the engine harness, and a green connector which connects to the underdash harness which has the 3rd ecu plug.

96-98 harness has 3 ecu plugs on the engine harness, and a green connector to connect to the underdash harness.

if that was confusing, i can take photos of what i mean, i think i still have my obd2a harness somewhere. or i can make you a diagram in paint. lol.

EDIT:: i know theres no sales in these parts of the forums, but i have a 96 underdash harness i dont need.. if that proves to be your problem.

 

Ahh. Yes thats the difference. I knew the 99 had one less.

 

This is what I found in the service manual:

96-98 have 4 ECU connectors (3 gray, 1 blue), but gray connector B is only for AT.

99-00 also have four connectors (3 gray, 1 blue), but none are specifically designated for the AT.

I did not see any green ECU connector for either.

 

The green plug is the dash harness. It plugs into the other green plug that should be somewhere next to the ECU.

 

yeah, the green connects the engine harness to the underdash harness.
for the 99-00 the A/T connector is connector D i believe (the little one)

 

I think you may be right.

 

96-98 is obd2a
99-00 is obd2b

Just use the right harrness. save the headache. and its not hard to wire vtec if you can't find an ex one. its only 2 wires