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11-24-2005, 10:49 PM

hondaboyz94si

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conversion

i want to know if i can convert my dpfi to mpfi just by using the mpfi wirring harness .i know i have to change the ecu, intake but is there something that i am missing or is just that easy?.and one more question how hard would it be to put a 95 1.6 civic motor in my 91 rex its a dx.do i just need the ecu and harness?

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11-24-2005, 11:16 PM

mr. carpenter

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Re: conversion (hondaboyz94si)

it's not that easy. search mpfi and make a good list of the actual steps. there is some rewiring that has to be done at the ecu and distributor

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11-25-2005, 01:28 AM

mattie_96

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Here is my MPFI swap write-up

. If done properly as to my instructions, then you will notice the amazing nite/day difference from DPFI

Ready, steady, Read!

1.) Use the existing dx wiring harness
-using the dx harness you have to extend the 3 TPS(throttle position sensor) wires 14 inches and depin and switch the 2 outside wires around.
-you also have to extend the EACV wires(blue/yellow and black/yellow) about 9 inches.

There will be 4 new wires that will be ran into the engine bay from the ecu area.

The first 2 wires will be coming from the "A" ecu harness plug and they will be ran into the engine bay as one will go to one injector wire and the other to its own designated injector plug wire

2.) You will have to cut the existing wires at a3 and a7 on the "A" harness plug. Then connect the new wire from a3 to the RED injector wire.
Proceed to connect the wire you ran from a7 to the engine bay as well and connect it to the YELLOW injector wire.

3.) Now you will have 2 more injectors left to wire. One will have a BROWN wire and the other will have a BLUE wire. Connect the solid YELLOW wire from the existing DX injector(cut at the plug and use the solid yellow wire right now as opposed to the black/yellow one)...to the BROWN injector plug wire from your donor harness.
Proceed to look for the RED wire from the DX injector(just cut the old dx injector plug off so you are left with the wire)...then connect that RED wire to the only other donor Si injector wire that is left which is the BLUE wire.

4.) *OK NOW! if the donor injector resistor box plug is left in tact with the 4 red/black wires from the plug going to each of the designated 4 injectors then you are good for the next step, But if not..then remember when you just wired up the 4 wires to their designated si injectors?????...welll if you remember than you will also know that for each of those injectors, a black/red wire is required, so connect each red/black wire(4) from the resistor box to each injector's red/black wire now(4).*

5.) Also from the injector resistor box there is a black/yellowwire...like I said before if the harness is still in tact and not cut(referring to how you got the si harness) then it will be easier to connect the black/yellow wire from the resistor box to the black/yellow wire found on one of the old DX injectors.
** DONT mix this wire up with the solid yellow one please**

Ok if you read everything over 3X before and after you got physical, than its time for the next step.

6.) The other 2 wires that are ran to the engine bay from the ECU area are the Crank Position sensor wires. *****THESE HAVE TO BE SHIELDED
so dont be lazy as SHIELDED WIRE CAN BE picked up at your local specialized electrical store, not home depot or others because I tried.*****
Just get the "shielded 2 conductor" wire that is 18guage...it will most likely be solid copper as opposed to the many stranded coppers but its fine and solders easy. I wish someone told me this sooner when I was doing my swap.

7.) Ok now you have to look at the ecu plug "C" and cut the ORANGE c1 wire about 1.5 inches passed the actual pin as you will have to solder another wire to it so you want some length to work with. The same goes for cutting the WHITE c2 wire. Ok now that the you have atleast 1.5" of the ORANGE wire that is coming from the pin c1 on the "C" plug ....solder one of the wires from the "2 conductor" shielded wire(wire 1 out of 2) to this Orange c1 wire
*remember which wire from the shielded you used...they are usually in black or red...so write down which one you used for c1-orange wire*

8.) Now you are left with the WHITE C2 wire, with about 1.5" exposed.
So solder the left over wire from the shielded "2 conductor" wiring(wire 2/2) to the WHITE c2 wire and electrical tape cleanly or shrink tube if you wish after soldering.
Also you will have a little ground wire in the shielded wiring, you can cut to just where the 2 wires are exposed from the shielding and tape the ground so its not touching anything. However you will have to ground the other end of the shielded wiring ground to a good ground. (I used grounded it via a self tapping screw to the engine mount area as there are a few small unused holes in the metal)

9.) Ok now you have to take care of the OTHER ends of the FORMER C1 orange and the FORMER c2 white wires. Try to untangle them from the harness to get a good amount of length to solder correctly.
Ok NOW look at the "B" ecu harness plug . Look for the pins B10 AND B12. They should be empty, most likely b12 has a white wire w/red stripe.....dont worry about it if you DONT HAVE an Automatic transmission.
If you have a manual tranny go to the next step.

10.) You will need to find an old "B" or "C" type of plug so you can take the 2 required pins with plenty of wire at the ends and add them to slots b10 and b12. If you have a wire in b12 and your sporting the manual tranny then cut the white w/red wire about 2" from the pin and solder the FORMER c2 WHITE wire to this b12 pins' wire.

Now if you have found a pin with wire at the end, go ahead and add it to the empty slot in b10....use your common sense on how it clips in...it should be relatively self explanatory and obvious if it went in correct.........
Now solder the FORMER c1 ORANGE wire to the wire from pin b10

So now you have taken care of the ecu side for injector wiring. Just be sure to electrical tape the ends of any exposed/cut wires as they will ruin your life if you dont (shorts=blown fuses=fires=crying)...so do that first.

11.) Ok injector wires are wired. Your 2 shielded wires with your mental record of which shielded wire went to which c1 or c2, are also wired. So that means you should be done for wiring on the inside of the car near the ECU. Now lets move on to the last Engine bay wiring that consists of using the shielded wire that you wired on the ecu side already.

Ok now its time to do some distributor wiring. On your si distributor you got for your mpfi swap(dx one wont work), the Round donor plug as opposed to your square dx plug, will have 2 extra wires (blue/green >c1 and blue/yellow>c2).

12.) If you were lucky you got the other round plug(engine harness side) that connects to the si distributor plug(round). If you did or didn't, either way solder the blue/green wire coming out of the dizzy to one of the DESIGNATED Shielded wires that came from pin c1. If you recorded which shielded wire you connected to c1, then you get a hero biscuit from me

Now connect the other shielded wire that came from pin c2 to the blue/yellow wire from the dizzy(or the other end of the round plug you got if you were lucky like I was).

13.) Now assuming that you got both sides of the Si dizzy plugs,right now...with the expectation that you made a black mark on one of the pure white wires as there are 2 that look the same and can be easily confused.....depin all of the wires from the square DX dizzy plug and transfer them to their appropriate location on the Si plug as all the colours will match up.

***IF you did end up switching the 2 white wires and dont know, its very easy to tell... you wont get any spark....haha....I did this so considering how easy it is to depin just switch the 2 white wires around if you get no spark, unless you are positive they are in their loving homes*****

DX parts you can still use
-dx throttle cable(use si throttle cable bracket so you can adjust)
-dx fuel line from rail to filter
Get the proper si parts sooner or later....because the dx throttle cable is longer and likes to bind.

Now that all of the wiring is done install your SI intake manifold.
PLEASE!!! dont use that retarded intake manifold brace! thank you.
Once you have cleaned the Si manifold completely (ports,gasket surface) with throttle body cleaner and installed your new intake gasket, install the intake manifold. Snug the intake bolts in about 4-5 stages working in a circular pattern(like small block chevy headbolts type procedure) from the middle outwards.
Once all of the bolts are evenly snugged and your confidence goes up because you put a new intake gasket on, tighten the bolts once again with a 12mm wrench. Its near impossible to get in with any sockets to torque so just use a long 12mm wrench.

Once all of the bolts are tight connect the necessary coolant hoses to the EACV valve as well as the green plug that you extended. Connect the white plug that was untouched from your dx harness to the IAT(intake air temp) sensor on the side of the SI intake manifold. Now connect the switched TPS plug to the TPS on your new si throttle body. Connect the necessary coolant hoses ***the si one is needed***(big U with one longer end to its appropriate place from the intake to the bottom fitting).

Now connect the brake booster hose to the same size fitting on the intake manifold. Also connect the fuel return rubber hose to the fuel rail fitting. Connect the MAP sensor vacuum line to the port on the back of the manifold and connect the other line from the Throttle body to the charcoal cannister solenoid. Connect the fatter hose from the charcoal cannister to the correct port fitting on the throttle body.

Now about the rear manifold brace, you can use it if you wish but the manifold is very light so the brace really serves no purpose in this case.
BUT if you are paranoid than elongate the 2 bottom bolt holes( offset) on the bottom of the brace In the end try to get the part of the brace that bolts on to the bottom of the intake manifold the most snug. You will most likely end up only getting one of the bottom bolts into the block but one is enough in this case.
Just make sure its securing the intake NOT PULLING IT DOWN OR UP as you will get a big vacuum leak(5500RPM GHOST REVVING ACTION) as the intake manifold bolts will back out. Make sure everything is snug and you are set.

Picture shows the MAP vacuum routing as well as the charcoal solenoid, and the pic of the DX throttle cable looped once.

I sort of cheated and used the DX throttle cable bracket that needed a little bit of modifying to work.

Pic below of how I used the dx fuel line, just make sure you dont crimp it and remember to keep it as straight flowing as possible.

This is an EACV valve

This is an FIV(fast idle valve), which you can just block off the port as it is not required. The wiring is the exact same as the dx's Tandem valve (blue and black/yellow) and the FIV wires when using your new si ecu "pm6" are on the same pin as the old ecu's tandem valve wires.
I think you understand now what I mean

....So unless the wire branches out somewhere else rather than going straight from the ECU to the FIV"si"/Tandem valve"dx", then technically those should be the wires. All it does is increase idle for faster warm up

Before I did the mpfi swap, using my Beltronics Vector and a Gtec Pro, I was running 17's in the 1/4 mile and thats WITH 2 1/4'' exhaust, 3'' cone filter, and a stock exhaust manifold.

Today after getting a crappy 4-2-1 Ractive header, and a 3'' short ram intake piping and a 3'' cone filter, and crappy all different brand name 35% tread left tires (25 psi) on 13'' steelies, I ran 15.65@88.0mph with a 0-60 of 7.08mph and 60foot time of 2.40seconds.

The dx cam(d15b2 16 valve) actually gives WAY more bottom end torque then the "si" d16a6 cam until about 5000rpm where it does down.
I have since installed the d16a6 cam along with a d16y8 cam gear(d16y7 will also work), readjusted the valve lash to a6 specs, but using the 1.5l(d15b2/d15b7 instructions as thats whats required) and I have ran a 15.46@93.2mph on the gtec.
At the track BEFORE the y8 cam gear install which fixed the 1.6l cam in a 1.5l block( a6 and b2 heads are the same) timing issue, I ran a 15.6939@86.54mph on my 205 000km d15b2 and stock clutch and DX tranny and severly retarded ignition timing with backfires each 7200rpm shift.

The new "668 hybrid". D16Z6 block and crank/D16A6 pistons and connecting rods/D16Y8 cylinder head.

Good luck, you'll be fine if you follow the directions--contact me if you have questions. Bye for now

Modified by mattie_96 at 11:04 PM 12/25/2006

Modified by mattie_96 at 2:14 PM 7/2/2007

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11-25-2005, 12:31 PM

mattie_96

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Also I decided to use shielded wire for the 2 injector wires that were added from a3 and a7...just to get the best signal possible to the injectors. I dont know the actual difference but everything works flawlessly.

I figured maybe my write up would be full of a bit more specifics compared to others as I know I wish I had a few like these available when I was doing the swap.
I hope it helps other people out as I already went through the trouble of unexpected problems and solutions.

Dont pay someone to do it, find time like I did and make it a DIY project. Goodluck on any MPFI swaps honda people

Modified by mattie_96 at 10:44 PM 12/25/2006

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