1990 CRX

ok i have a serious question!i dropped the jdm d15b sohc vtec in my rex(love of my life)but ran into a lil problem!i installed the sub harness obdo to obd1 with a p28 ecu.the problem is,do i use my old obd0 engine harness and cut/splice the plugs that hook to the engine?or do i use an obd1 harness?i know im going to have to cut and splice no matter what,but whats a better route?i have both wiring harness.how did you do yours?i heard i can use my old harness just cut the plugs from the obd1 and solder them to the old one,but just the plugs that plug into the engine not the ones coming from the fire wall.Another thing is,how do i switch my rex from dpfi to mpfi?i appreciate any info!

RoughKnight

there are alot of threads on going from dpfi to mpfi, and even more about the d15b as it's getting more and more popular. Google is your friend, the HondaSwap Forums search bar is closer however

1990 CRX

THATS WHY IM ON HERE!I TRIED GOOGLE BUT IM INPATIENT AND NEED MY BABY ROLLING BY OCTOBER.

D16SiHatch

search for dpfi to mpfi, you'll find what you're looking for to do the conversion.

as far as your engine harness, you will retain the stock harness and simply run a few wires into the bay for the 4 wire o2, vtec, etc.

__________________
91 Civic Si
b18b1, I/H/E, 6000k HID kit, 94 teg cluster
Parting mustang out to buy another civic

1990 CRX

do you guys know if its necessary to convert it to mpfi?and im right about using my old harness but attaching the connectors from the new one right?

D16SiHatch

if you intend on having vtec and using the proper ecu for that engine, then you must convert to mpfi. and yes you connect your old harness up to the new engine.

__________________
91 Civic Si
b18b1, I/H/E, 6000k HID kit, 94 teg cluster
Parting mustang out to buy another civic

1990 CRX

jlicrx

you need to use your DPFI engine harness and make the MPFI wiring changes to it - the changes include adding the wiring for the injectors to the harness, adding injector wiring from the ECU and adding the wiring for the cylinder sensor at the distributor

ECU WIRING CHANGES
1. You will need a couple of 'B' or 'C' ECU connector wiring pins with short piece of wire for adding wiring to the ECU.
2. The following changes need to be made to your original DPFI chassis harness where it plugged into the ECU.
3. De-pin the Orange wire at ECU pin C1 and re-pin it to ECU pin B10, which should be empty.
4. De-pin the White wire at ECU pin C2 and re-pin it to ECU pin B12, which should be empty. If there is a wire at B12, just de-pin it and leave it.
5. Cut the Yellow wire at ECU pin A3 and leave a short piece of wire on the ECU connector. Leave the wire still in the harness not connected to anything. Splice a new wire to the short piece of wire remaining in the ECU connector. This wire needs to be long enough to be routed with the harness out to the engine bay and reach the injectors. Label this wire A3.
6. Cut the Red wire at ECU pin A7 and leave a short piece of wire on the ECU connector. Leave the wire still in the harness not connected to anything. Splice a new wire to the short piece of wire remaining in the ECU connector. This wire needs to be long enough to be routed with the harness out to the engine bay and reach the injectors. Label this wire A7.
7. Using the pins with short piece of wire from Step 1 above, insert one pin into the 'C' connector at C1 and insert one pin into the 'C' connector at C2. Splice a new wire to each of these short wires and run them out to the engine bay to the distributor. Label the wires C1 and C2 respectively.
8. This completes the ECU wiring changes.

UNDER THE HOOD WIRING CHANGES
First, you are going to need to rob some connectors from the OBD1 engine harness. Specifically, they are the injector wiring, the distributor connector and the connector for the cooling fan switch.

INJECTOR WIRING
1. For the injector wiring, cut the tape and remove the black plastic wire looming and you will find that the injector wiring is a separate harness all to itself. This harness will need to be added to your DPFI engine harness as follows.
2. Each injector clip has two (2) wires going to it. The injectors are numbered the same as the cylinders, i.e. #1 closest to timing belt and #4 closest to the distributor. The injector clip for injector #1 has a Brown wire and a Red/Black wire, #2 has a Red wire and a Red/Black wire, #3 has a Light Blue wire and a Red/Black wire and #4 has a Yellow wire and a Red/Black wire.
3. Cut all of the wires close to the connector at the end of the injector harness opposite from the injectors.
4. On the DPFI harness, there are two (2) fuel injector connectors, one is a Brown connector with Red and Yellow/Black wires and the other is a Green connector with Yellow and Yellow/Black wires. Cut the wires for these connectors as close to the connectors as you can.
5. Find all four (4) of the Red/Black wires coming from the injector clips along with the two (2) Yellow/Black wires that went to the DPFI injectors and connect all six (6) of these wires together.
6. Connect the Yellow wire that went to the Green DPFI injector connector to the Brown wire at injector #1.
7. Connect the Red wire that went to the Brown DPFI injector connector to the Light Blue wire at injector #3.
8. Find the wire from the ECU labeled A3 and connect it to the Red wire at injector #2.
9. Find the wire from the ECU labeled A7 and connect it to the Yellow wire at injector #4.

IACV WIRING
1. The IACV connector on the DPFI engine harness is a Green connector with Blue/Yellow and Black/Yellow wires. You need to extend these wires, by cutting each and adding a short piece of wire, so that the connector will reach the IACV on the MPFI engine, which is on the back of the intake manifold.

THROTTLE POSITION SENSOR WIRING
1. The TPS connector has three (3) wires, Yellow/White, Green/White and Red/Blue. You will also need to extend these wires so that the connector will reach the TPS on the MPFI throttle body. When you are extending these wires, switch the position of the Yellow/White and Green/White wires so that the Yellow/White from the harness is connected to the Green/White on the connector and the Green/White from the harness is connected to the Yellow/White on the connector. This is because the TPS on the MPFI rotates opposite from the TPS on the DPFI.

COOLING FAN SWITCH WIRING
1. The cooling fan switch on the OBD1 engine is located on the thermostat housing and is on the back of the block next to the oil filter on the OBD0 engine. You need to cut the wires at the OBD0 connector which has a big round black rubber boot on it. The wire colors are Yellow/Green and Black. Splice the connector that you robbed from the OBD1 harness onto these wires. Color doesn't matter, as it is just a switch to ground.

MAP SENSOR WIRING
1. The OBD0 car had the MAP sensor mounted on the firewall where the OBD1 engine has the MAP sensor on top of the throttle body. The MAP sensor connector is not on the OBD0 engine harness, but is on the chassis harness. You need to extend the three (3) wires for the MAP sensor connector so that it will reach the MAP on the throttle body.

OBD0 TO OBD1 ECU JUMPER HARNESS
1. If your jumper is for a VTEC engine, then the wiring should already be there. If not, you will need to run the necessary wires to the ECU.
2. If your jumper harness included the wiring for the 4-wire O2 sensor, you are good to go. If not, you will need to add wiring.

DISTRIBUTOR WIRING
1. If you purchased an OBD0 to OBD1 distributor jumper, you are good to go. If not, you will need to splice the connector from the OBD1 engine harness onto the DPFI engine harness.

__________________
ZCspeed Racing

1990 CRX

ok!my obd0 to obd1 jumper is for a sohc vtec,and some dude on here said all i had to do was add the extra wires for my injectors.on the info above it reads at the bottom"If your jumper is for a VTEC engine, then the wiring should already be there.do i need to buy a dpfi to mpfi harness as well??all the info you guys gave is helping me alot!thanks

89hatchd15b

from what I understand to do the dpfi to mpfi you just add wire there is no conversion to buy

Manny 77

If anyone is reading this i need helpppppppppppppp.... i got a d15y7 engine i swap the head for a vtec head from a d16 engine with the p28 ecu that i get from a 93 civic ex automatic (my car is a 92 civic dx sedan) the car is runnig good except for the code 19 that is showing, i look that up and its a code from some automatic transmision sensor or whatever but my car is manual and i heard that if the check engine light in a vtec motor is on the vtec will not work so my question if theres any way that i can fix it or i have to get another ecu from a manual car????

Manny 77

If anyone is reading this i need helpppppppppppppp.... i got a d15y7 engine i swap the head for a vtec head from a d16 engine with the p28 ecu that i get from a 93 civic ex automatic (my car is a 92 civic dx sedan) the car is runnig good except for the code 19 that is showing, i look that up and its a code from some automatic transmision sensor or whatever but my car is manual and i heard that if the check engine light in a vtec motor is on the vtec will not work so my question if theres any way that i can fix it or i have to get another ecu from a manual car????

Manny 77

If anyone is reading this i need helpppppppppppppp.... i got a d15y7 engine i swap the head for a vtec head from a d16 engine with the p28 ecu that i get from a 93 civic ex automatic (my car is a 92 civic dx sedan) the car is runnig good except for the code 19 that is showing, i look that up and its a code from some automatic transmision sensor or whatever but my car is manual and i heard that if the check engine light in a vtec motor is on the vtec will not work so my question if theres any way that i can fix it or i have to get another ecu from a manual car????

89hatchd15b

The manual and automatic ecu's are different. I think you need a new one

jlicrx

you can modify the Auto P28 ECU to work as Manual

Moates Support : Auto to Manual

__________________
ZCspeed Racing

Manny 77

how do i do that??? with a chip i guess???

Manny 77

LOL i did find my answer in honda tech... but Desolder the resistors RP17.

Then, solder a jumper across RP18 and done you got a manual ecu...thanks guys

RoughKnight

^How long does it take for you to log into both accounts and disrespect our site? We have a reference section, and you have a search button. Next time you want to "create fake users" to give yourself a popularity boost and denounce us, please go fuck yourself. Thanks.


I bet $10 both users' ip's match.

D16SiHatch

i would take that bet lol.

this manny guy is the same guy over at honda-tech who has posted literally the same thing like 7 times in other peoples threads asking about how to put a vtec d16y7 head.. (note: vtec y7 head does not exist) onto his d15y7 bottom end (also note: no such thing as a d15y7). this guy is full of fail.

__________________
91 Civic Si
b18b1, I/H/E, 6000k HID kit, 94 teg cluster
Parting mustang out to buy another civic

1990 CRX

anyways,how do i add wires and where to?im starting the plug soldering this weekend all im missing is the extra wires to make it mpfi!whos done this sawp?any info helps,thanks guys!

D16SiHatch

jlicrx already posted what you need to do to go from dpfi to mpfi.

you may also find this writeup here useful
DPFI to MPFI writeup

__________________
91 Civic Si
b18b1, I/H/E, 6000k HID kit, 94 teg cluster
Parting mustang out to buy another civic

RoughKnight

^ ^ He already posted the answer...Too lazy to do the work? :P

1990 CRX

RoughKnight your a fagget!lol

INJEN78

then leave.and dont come back..

__________________
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good and fast isn't cheap

RoughKnight

...did your engine blow up yet?
another e-thug, how nice.