Hello Honda-Tech,

My gf has a 91 civic lx sedan. The body is still in really good condition. I found another d-series engine from a 99 civic cx hb that I got from the junk for cheap. I was wondering if I would I need, ECU, wiring harness, tranny, sensors, ECt... Or if could i just swap out the engines. Any help is greatly appreciated.

Thank You.

 

what d series motor did you get? I would think that would be he y7 right?

 

your gonna need to go obd2, Wire up some stuff and get a 99 CX ecu

 

yes its a y7.

 

so i couldn't use the old ecu? what kind of wiring would I have to do?

Thanks

 

He is incorrect. You don't need to convert to obd2. hell you don't even need to convert to obd1. the y7 has very similar specs to the a6 and will run just fine with a pm6 obd0 ecu. if you just need the car to run for as cheap as possible though then i wouldn't even bother converting from dpfi to mpfi. just use the old dpfi manifold on your new engine and use your current ecu. if you were to convert to mpfi though, then you would use the pm6 ecu.

 

What would I need for wiring? would I use the harness from the a6 or the y7? what sensors am I going to need to get?

Thanks for all the info.

 

Off the top of my head, the quickest way to get it in there is a straight one for one swap with your old motor using your original intake and exhaust manifolds. The only difference is the thermoswitch for you radiator fan will be different. You'll need the matching plug from the newer harness (or make your own connector) and you'll have to cut/splice it to replace your old connector.

Next step up would be to convert it to MPFI (see FAQ for procedure), basically you'll end up with something nearly equivalent to the Si engine for your year and you'll run the corresponding intake manifold (any D-Series MPFI manifold with the appropriate provisions for the neccessary/existing sensors should work just fine) and ECU.

Final step up would be to run it either OBD1 or OBD2. Obtain a conversion harness for the easiest method to run the correct ECU per OBD.

 

Which engine wiring harness would I use? Ek or EF?

 

The one for the car. Not the engine. The connectors are different.

 

One last question, would i use the OBD0 dizzy or would i have to get a harness for the OBD2B dizzy? Thanks for all the answers, I really appreciate it.

 

Match the distributor to the ECU.

 

Ran into another problem. On the pre OBD engine, There is sensor with a broken prong, and I'm not sure where it goes or if it is needed on the obd2b engine. First picture is of the D15 and second is of the D16.

 

That plug that is broken is your fan switch. I believe the OBD2 engines have the same configuration as the OBD1 engines with respect to the fan switch. If I'm correct, the fan switch should be on the thermostat housing. If you want pics to compare, look in the FAQ for D16Z6 block with D16A6 head. I did the write up for that and ran into the same challenge.

 

ok my gf's dad started taking the alternator apart from the d15 and broke some of the winding. I was wondering if i could use the alternator from the d16 and splice the wires together.

Thanks for all the feedback.

 

Ok finally, done with school for the semester... Now i can acutally get this project completed.... So i can run this d16y7 with the dpfi mani, dizzy, and ecu?