Vitalspeed_CRX

Before I did my conversion, I had a real hard time looking online for the right way to do the conversion including what parts I need and what steps. It was pretty much pointless to keep looking online. A friend of mine sent me to a link and im going to share it with everyone cuz I know it was a bitch looking for help. This is for the people who where in my shoes before the conversion (STUCK) so here you go. Hope it helps.

DX,STD (DPFI) -> Si,HX (MPFI) wiring
PARTS/TOOLS NEEDEDPrices 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
- Manifold Support Bracket ------$0-$10
- 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 may also be cheaper if you buy everything from one person all at once



MPFI manifold on left, DPFI manifold on right.

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 actually at idle. I highly recommend soldering and heat shrinking any electrical connections you will be making because it is very possible for connectors to come loose from all the vibration and solder will hold up better in the long run. Also, the TPS and EACV plugs are too short and they'll have to be extended. You're also going to have to switch the manifold support bracket, since the bolt parrern from the support to manifold is different from DX to SI, although they still bolt up on the block the same.

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. I used the TPS connector off the Si harness, just so that I could just match up all the wires, since the wires are already reversed on it.

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 on the ECU side 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

Distributor wiring completed


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.



OBD1 ECU PINOUT
The # go up and down from left to right.(see)


Another thing make sure you have extra pin inputs since you will cutting the wire and not taking the complete wire out of its socket.

HOPE ALL OF THIS HELPED SOMEONE.

eg6sir

nice write up.. we have one already.. but maybe it'll replace it..

DPFI to MPFI writeup

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CRX-YEM

Very Nice, I'm planning on doing this soon, I'll presume a P28 ecu can be used in place of a PM6

although I noticed some duplicate information. If you don't edit it yourself to make the corrections in a few days, I'll fix it for you.

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Dennis

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Mondaswap For Sale - MPFI, 88-91 CRX, 92-95 Civic Parts

Please don't PM/Email/IM me for technical support. Make a Post!!!

91 CRX DX, 03 Civic EX

"There are 10 kinds of people in the world: those who get binary and those who don't."

"Of all my imaginary friends I don't think there was one I didn't end up having to kill"

Vitalspeed_CRX

Edit has been done. Thanks

Walterronny

nice but i got problem trying to do this conversion

help me out..

DPFI to MPFI, engine harness problem?

Enigma9789

I have to say....(though i didnt use this diagram)

that the DPFI to MPFI swap is one of the best power upgrades you can do.

I used a Z6 intake and A6 dizzy with a PM6 ECU, the power difference is like adding a small turbo that spools instantly, I noticed great power differences in the swap. taking off from a stop spinning tires it will spin all the way through 1st and let off a nice squeal in second. where befor it would chirp in second and barely spin through 1st... plus going from 6750 redline to almost 7500 is nice too!!!

just thought id share my story

efnick

im gonna try this in my ef it makes more sense each time i read it and go look at my car, but how do i pull up the carpet to get to my ecu? its hel down by these flat-headed plastic screws or sumthing, and i dont wanna just break them off or tear the carpet... do i need a special tool, where the phillips head pattern would be in a screw head, it has 4 holes?

Vitalspeed_CRX

The the plastic bolts should just be able to pop out , lift them up a little, place flat head under and pop them up the bolt just has layers of plastic teeth which looks like this.
(good ole MSpaint)

There just push in bolts just a little harder to pull out because of the angle of the teeth on them. There is no special tools just pull them out you can push them back into place when your done.

PuddleSkipper

I was wondering why is this conversion always listed for a Std/DX coversion to MPFI and why the LX is never listed? Even at places like Rywire.com that sells conversion harnesses. Is the wiring in an LX that much different or is it simply forgotten that these cars came with the DPFI injection as well?

RoughKnight

dx/lx same thing

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PuddleSkipper

Thanks

jlicrx

the original thread here is 2 years old but since it is up, i thought i would point out that the diagram for the distributor wiring is not correct - the 5 DX wire colors should match the same 5 Si wire colors on both sides of the connector

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