dpfi to mpfi?

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little88hatch

Junior Member
ok, so i have an 88 dx hatch and i just put a b18a1 that i got for cheep in it for fun but i need to wire it in... i have the full stock harness out on the hatch and i also have most of the harness from the integra that the engine came out of... i dont know how to bring it from dual point injection to multi point injection. i would like to know which wires from which vehicle i have to use and the easiest way that any one knows of to make this thing run so i can put it all back togeather, i also have all the shit on the fire walls of both cars and need to know which of it i need to use so i can clean up the engine bay too. its a total mess and any info that any one can provide for me is greatly appreatiated.
 
MPFI SWAP

1. FIND WIRE COLOR

2. FIND PIN LOCATION

3. 3 COLOR 3' WIRE

4. SOLDER AND SOLDER IRON

5. OBD0 ECU (P30)

6.INJECTOR RESISITOR BOX OBD O ( SI OR HF)
*SINCE IM USING A SI HARNESS DO NEED TO RELOCATE THE INJECTOR WIRES ON THE FEMALE CONNECTOR

WIRING UP CRANK POSITION SENSOR IS ALSO MANDATORY

ALSO IF USING A CABLE TRANNY YOU MUST CHANGE THE SPEED SENSOR

MAKE SEPARATE HARNESS FOR INJECTORS 1 THRU 4

MUST INTERGRATE A WIRE AND CONNECTOR FOR KNOCK SENSOR

VTEC WIRING WILL NEED TWO CONNECTORS AND THREE WIRES ( 1 IS GRND)

7. DISTRIBUTER WIRING (IF MOTOR IS OBD1)
• WHITE - YELLOW/GREEN
• THIN WHITE - BLUE/YELLOW
• BLUE/GREEN - ORANGE
• BLUE/YELLOW - WHITE
• ORANGE/BLUE - ORANGE/BLUE
• WHITE/BLUE - WHITE/BLUE
• ORANGE - BLUE/GREEN

PARTS/TOOLS NEEDED:(Prices are in canadian currency and may vary depending on where you go)
- Si ECU(PM6 for manual transmission) -- $75-$120
- Si Distributor -- $50-$120
- MPFI intake manifold - including throttle body, fuel rail, injectors -- $70-$90
- Resistor Box(88-91 Si) -- $20-$40
- Si wiring harness(needed for injector plugs, injector resistor box plug, and distributor plug) -- $0-$10
- Intake manifold gasket- (not needed but recommended) -- $15-$20
- Si fuel line from filter to fuel rail -- $0-$5
- Some extra wire -- $3-$7
- Electrical tape or heat shrink(better) -- $1-$10
- Wire stripper/cutter -- $5-$15
- Soldering gun and solder(not needed but highly recommended) -- $10-$18

Parts could cost anywhere between $230-$405 depending on what kinds of deals you can find and where you get them from

It is much easier to use your existing DPFI harness and just add the extra 4 wires that will be needed. The Si harness will be much harder to use.

There are two major wiring changes that you'll have to do going from a DPFI system to an MPFI and a couple other minor things that need to be done too. The first one is the crank angle sensor wiring which is the easy part. The second one is the fuel injector wiring which is slightly more complicated. Also, you'll have to switch the two wires on the TPS because the TPS on the new intake works in the opposite direction. If you dont switch them, the ECU will think that the engine is at Wide open throttle when its at idle. I highly recommend soldering any electrical connections you will be making because it is very possible for connectors to come loose from all the vibration. Also, the TPS and EACV plugs are too short and they'll have to be extended.

TO HOOK UP THE MULTI-POINT CRANK ANGLE SENSOR: - First, you'll have to go to the passengers foot well to where the ecu is located.
- Pin B10 and B12 should both be empty.
- You'll have to cut and move the wire that goes to pin C1(orange) over to pin B10, and move the wire from pin C2(white) over to pin B12. Don't get these two mixed up or else the ignition timing will be severly retarded. Leave enough wire at the ECU side of pin C1 and C2 for next step.
- Now run wires from pins C1 and C2 into the engine compartment and label them.
- There will be a connector on the new Si distributor with two unused pins. One of the wires will be blue/green stripe, and the other will be blue/yellow stripe.
- The wire that is blue/green stripe will go to the wire from pin C1 on the ECU and the other wire that is blue/yellow stripe will go to the wire from pin C2.


SWITCHING THE WIRES AT THE TPS:
This pretty much explains itself, just switch the two outside wires(green/white and yellow/white) around at the TPS and then you're done this step.

INJECTOR WIRING (In the car):
First of all, while you're still in the passengers footwell, cut wires A3(yellow) and A7(red), although leave some wire for later use. Now run wires from pins A3 and A7 into the engine compartment and label them.

(Engine Compartment):
- Mount the injector resistor box up on the drivers side shock tower.
- Connect the yellow/black wires from the two DPFI injector harnesses and run it to the yellow/black wire on the injector resistor box.
- Connect the yellow wire from the DX injector to the #1 injector (brown wire).
- Connect the red wire from the DX injector and run it to the #3 injector (blue wire).
- Connect the wire you labelled A3 to the #2 injector (red wire).
- Connect the wire labelled A7 to the #4 injector (yellow wire).
- Then, connect the 4 red/black wires coming from injector resistor box to each of the four injectors.

Completed Wiring Diagram

You should have three extra plugs left over after you are done the swap. two of them are the old DPFI injector plugs, and the other one is for the tandem vavle for the DPFI system, which you do not use on the MPFI system, you can either just cut it off, or tuck it away somewhere.
 
In his instructions you probably wont want to use the pm6 ecu. use the ecu for the engine.
 
what will i have to get to hook up the b18 ecu to the stock ecu plugs do they make a plug in type thing to accomodate the new ecu? thanks to all that have replied so far this info will be a big help to me
 
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