1990 honda Civic EF hatchback.

Look. I know there's a million threads that talk about this and there's no reason to get mad about my post. I just need a simple answer because for some reason I am confused since I'm doing more than just DPFI to MPFI swap but turned it into OBd0 to Obd1 swap also.


Where does the the 4 black and yellow wires go? I have a OBD0 harness. I see answers saying it goes to the plug on the shock tower if you have a OBD1 Harness. And for some reason I'm under the impression they get soldered together then a wire running to the A15 port of the ECU harness?

I need help and don't know how I got confused.

Most people do a DPFI swap then later on do a OBD0 to OBD1 swap. So doing both made it a little confusing since there's no need for the resistor box.

 

The 4 BLK/YEL wires coming from the injectors is the switched 12V. On the OBD1 engine harness, the "dead end plug" on the driver's shock tower is the 12V power distribution point for the injectors, IACV, O2 heater, etc. On an OBD0 ECU, A13 & A15 are switched 12V power supplies.

Which harness are you planning to use?

 

Who says you don’t need the resistor box?

 

Using the original STD harness and following GaragebuiltHondas on YouTube guide.


Car doesn't start now that I finished the swap ☹

 

A few people on here and GaragebuiltHondas YouTube tutorial on OBD0 to Obd1 says you don't need the resistor box anymore.

 

Tell me you did all that work and didn’t go vtec?!?!?!?!?

 

I do have a y8 head but I didn't put it on yet 😆

No vtec yet 😔

 

And you ain’t gonna put it on. I won’t explain

sell it

y do people keep doing mpfi swaps without vtec

garage built Honda’s ain’t doing anyone any favors

 

I'll get around to it in the future. Already having enough issues as is with getting the car to run. After doing the swap, the injectors aren't working. Sprayed starter fluid into the intake and it runs momentarily. Could be these old injectors. They've been sitting for about 5 years.

 

The resister box has nothing to do with if the ECU is OBD0 or OBD1, it has everything to do with the type of injectors you are running. Honda originally used low impedance (peak and hold) injectors but switched to high impedance (saturated) at the same time they switched to OBD1. Low impedance injectors require the resister box, high impedance do not. It is entirely possible to use low impedance injectors with an OBD1 ECU. Running an engine using low impedance injectors without a resistor box can damage the ECU.

https://www.hondata.com/?_route_=tec...ance-injectors

 

Thanks for the great info. They're mystery injectors. So it's quite possible they need the resistor box.
going to take the OBD2 injectors out the 96 EK and see how those do.

 

Got me praying I didn't burn up the ECU now 🙏

 

Check the resistance on the injectors. If I recall, 10-12 ohm is high impedance (no resistor box needed), and 2-3 ohm is low impedance (you should run a resistor box).

 

Just an update. I took the fuel rail off with the injectors attached and turned the key over and only 1 injector was spraying fuel. I took the injectors out of the EK I have and out them in and the car runs now but it's throwing a code 8 and code 14

 

he can do that fancy stuff or he can google what obd0 1 and 2 injectors look like on top