milkwasabadidea

ok i just got a obd2a 98 hx motor.... its complete with the obd2a harness and ECU.... i want to run the motor in my 99dx civic which is obd2b.... if this was any other simple motor id just change what needs to be changed.... but considering that this is a HX motor. i will need to use the original engine harness and ecu..... now i know it wont work on my car.....

so what are my options? because i really dont know and i want to do it right the first time

and to add i have the actual shell that the hx motor came out of so i can use it as a doner car for anything i need

B serious

iTrader: (1)

?? Is your 99 civic an EX? DX? LX? HX? Si? Auto? Manual?

You use the harness that came with your car. Plug it into the engine. You probably have to re-use your old distributor. But the 96-00 civic had SO many different distributor plug configurations that I can't be sure on that one.

If your car already had VTEC, then I don't think you need to make any wiring changes. Everything should just plug into your OBD2B harness. Use a OBD2B computer from a HX.

Or...I guess you might be able to use your old ECU. IDK what model of car you have, though.

milkwasabadidea

dx non v tec

B serious

iTrader: (1)

Manual or auto?

milkwasabadidea

manual

milkwasabadidea

still clue less

fleabag

What is so confusing? Do a complete swap which means use everything that you can get from the donor car and replace what is in your existing car. This car won't pass smog or anything like that since you're doing an older engine into a newer car swap but aside from that if you want everything to run properly then that's the way to go. You can't use the OBD-IIb harness for the Y7 engine because there are far too many changes from the Y5 (HX) engine to make it work. Just do a complete swap and you should be fine. Btw the Y5 harness did not change from 96-00... (all HXs should be OBD-IIa)

milkwasabadidea

not saying its confusing im sure ill have to take alot stuff out the doner car but i was asking if there anything really important that i should not miss.. someone was talking about a egr control unit or something....i know im going to need the engine harness and cabin harness but if theres any other thing really important i would like to know so i dont screw it up...

fleabag

Well it's good you're concerned but if you swap everything without disconnecting much, it's unlikely you'll have any issues. I don't know how you'll do the swap but to prevent issues, if you can swap the entire engine fully assembled, then you should know that this will work out alright.

milkwasabadidea

if i use all the harness from the dash from the 98 hx shell... how will i get my 99-00 climate control to work .... thats one of my bigger concerns...

fleabag

I believe you can retain the cabin harness while still using the engine harness which does all the sensor plus plugs into the cabin harness and the engine computer. Good question though..

94EG8

You can't. Depending on which way you go you'll either be missing the "A" plug or have 2 of them and the speedometer and tach wont work.

All HXs were OBD2A, you could get a '99 -'00 HX cabin harness since they were OBD2A but setup for a '99 - '00 climate control.

fleabag

Did not know this.... question is, why did YOU know this?

94EG8

I dunno, I just did *shrugs* What's sad about it is we didn't even have HXs in Canada. The OBD2A/OBD2B thing is getting to be fairly well known though. Diagram below shows the difference:

milkwasabadidea

i remember there being a write up on how to get the obd2a harness working on a 99-00 climate control....

milkwasabadidea

also i was wondering if ill have to change/convert all the plugs that go into the driver side fuse box and the floor harness to the fuel pump....?

milkwasabadidea

motor is prepped and dash is prepped to be pulled.... just need a cherry picker now =/

Kista20

94EG8 is right you can get a 99-00 hx cabin harness and your good. I remember awhile back a user had a 99-00 hatch that actually did the same conversion, maybe that is where 94EG8 got it from. I remember they said it was a big pain but totally worth it in the end.

The egr that you are talking about is the egr valve. It would be a good time to clean it out since they need a good cleaning roughly every 100k or so.

milkwasabadidea

i doubt i will find a 99-00 hx cabin harness anywhere lol... but i will try to see if the 98 cabin harness will work with the 99-00 climate control some how... it shud work with a little tweeking cause ive seen some people with 98 doing 99-00 climate control keeping the 98 harness

as for the egr valve.. im planning on cleaning that soon and sea foaming the motor too... but im stuck though... no cherry picker !

Kista20

If you get everything setup properly you'll enjoy the 40+ mpg. They are fairly reliable just like any honda but they have their issues such as exhaust manifold cracking due to the fact the cat is part of the manifold as one unit and ecu problems. The dealer replaced my 97 for free under warranty and I have a 99 where someone had installed a cali spec which I'm guessing the ecu went bad and they couldn't find the correct part# and I can find those all over the internet just not the federal one and I'm not going to the dealership to get one. It runs fine and doesn't throw any codes but the best I can get has been 35mpg and the ecu is the only thing that would make that much of a difference between the two cars.

milkwasabadidea

yea thats the reason i picked the hx motor over the y7 . is because the gas mileage.... i wont b running the stock headers... im using 98 ex headers and cat.....i have to find a way to extend the second o2 plug all the way to the buttom. im expecting quite a few check engine lights when im done

milkwasabadidea

update:.......found a way to pull the motor... just lifted the car up very high and slide the motor out from the bottom lol.....the hx is in the ek... but I'm not done bolting everything up... will do tomorrow and haven't messed with the dash harnesses yet....

94EG8

You wont be getting HX type mileage without the HX stock manifold, moving the O2 sensor further downstream screws with the lean burn.

fleabag

Exactly.. There is a very good reason why the cars come with the things they do and it's clear these guys don't understand that. These lean-burn cars are complicated to get this kind of fuel economy and if you mess it up, it can easily screw up this equation.

milkwasabadidea

im running 98 ex headers.. the primary sits at the very top just like the hx and y7 headers and 99-00 ex headers sit like b series headers with the primary under the car on the header...... .. its the secondary that i need to extend and this set up is only temporary.. since i dont have stock hx or y7 headers/cat..... its either run it like this or no headers at all lol... plus im more concerned with getting the car started