Hi all,

I am sure this question has been asked previously but couldn't find in a search.

So I have installed em1 b16a2 engine, transmission, engine harness and ecu into my 97 ek civic. Everything went in fine, but after plugging ecu in and tried starting...car only cranks but no start.

So...there is no CEL, and no fuel pump prime.

Tried different main relay, same thing.

Checked fuses, all fine.

I was reading one forum saying i need to change from obd2b to obd2a.

But any help would be great.

 

What ECU are you running?

Did you reconnect and tighten the G101 ground on the thermostat housing?

 

So, you didn't use the '97 Civic engine harness ??? This means that you only have two plugs plugged into the ECU... missing the critical third plug that is found on your original engine harness. This is WHY you are having problems.
The fix is to modify your original Civic engine harness to fit the B16A2 engine... add/change any plugs necessary and lengthen/shorten what is required. Purchase an OBD-2A -> OBD2B ECU adapter and plug in your EM1 ECU. Turn the key.

 

I will grab a obd2b - obd2a jumper and give that a go...

thanks

 

No...you need an obd2a- obd2b...

 

Yes, you need this adapter harness... and you MUST use the '97 engine harness and modify it to fit your B16A2.

 

Yes yes, all that jazz up there.

 

Is wiring at the shock tower connector on the driver side differences being the reason the third plug is necessary at the em1 ecu in this situation?

 

That is part of it... but only a small portion. ECU output wiring is predominantly focused on the plug that is part of the under dash (cabin) harness on the OBD-2B combination... whereas, the OBD-2A engine harness has the 3rd ECU plug attached and output wiring is spread over all three plugs and converge into the green "crossover" plug. This is why there are soooo many more wires in the '96-98 green plug when compared to the '99-00 green plug.

The bottom line is ANYTHING can be made to work... but why work HARD when you can work SMART. It will always be easiest to start with the chassis/engine wiring in the car instead of mix/matching model year items. Changing a few wires and plugs on the engine is far more simple than changing a ton of wires and plugs inside the cockpit.

 

Ok, that makes sense. I didn't think about output wires from the ECU. That clears it up, thank you.