DPFI->MPFI help needed, throwing codes 4 and 16

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ee4wagovan

New Member
hey guys.

i have a 1991 Civic Wagon DX 2WD (EE2) and a few weeks ago i decided to do an MPFI swap. i read up a bunch on fourthgenhatch.net and a few other sites for the wiring.

also collect all the parts needed, got the complete intake mani, used PM6 dizzy, PM6 ECU and other random junk. everything was installed, go to start the car and it crank up bt instantly jumps to 3200 rpms and sounds like its at the redline going ba-da-ba-da-ba-da anyways. also ECU was throwing codes 15 and 4.

i took back the dizzy i had cause it was a used POS and just went ahead and bought a remanufactured one from Advance Auto for $120. i install it, crank the car and it idles perfect *yay* well not really, ECU is still throwing code 4 (crank angle sensor) and when i rev the engine it still only goes to 3200 rpms. wtf. i thought maybe i got a defective dizzy, so ireturn this for a different one. same problem occurs.

during this time i keep checking and rechecking all my wiring connections and reseach even more deeply the different wires and junk. no use.

4th week into project --

so i guess i eliminated the air and spank systems out cause i have researched them so much and everything seems to be right.

so i moved on to the fuel system, i fricking checked over the wiring to the injectors and everything. idk, still no change (as in im stil getting all the same symtoms, code #4 and not revving past 3200).

EXCEPT now im getting a NEW code, #16 = Fuel Injectors. haha its like God was telling me something. anyways. i checked into it a little and possible reasons for this are Resisitor box, bad injectors, Main Relay (which is NOT the problem fo sho).

-does this mean my resistor box could be messed up? or WIRING to the box?
-what if my injectors were bad would the car run at all? im pretty sure thats not the problem. i got them off a healthy engine from a friend.

one last point i might add, i pulled the spark plugs out from each cylinder and smelled inside to see if anything was weird. #4 and #2 cylinders smelled of raw gasoline, #1 and #3 smelled normal-ish, that is, didnt really smell at all.

when i rev the car up to 3200 it sounds like its misfiring, could it be the injector timing? and if it is..why? whats causing it? i checked the wiring over and over... damn it, idk.

please help me out guys! i need my car!


thanks in advance.
 
what kind of wirin did u use?..
when i did mine i ran 4 wires from my ecu to each injector.. the other 2 for the dizzy and 1 more for the resistor box.. it clear all my codes.. i never got it runnin cuz the head was bad.. but thats a different story lol..
i know theres more than 1 ways to do this swap..
this link really helped

https://hondaswap.com/swap-articles/dpfi-mpfi-writeup-49557/

doble check this step "On the TPS plug on the DX harness you will see 3 wires going to it, yellow, red, and green, in that order (if you are looking at the top of the clip from left to right on the DX clip). Depin and switch the green and yellow wires around so now the order is green, red, yellow. This is because the DX TPS sensor works in the reverse of the MPFI one, so if you didn't do that your car would think it was at redline when it was suppose to be at idle. So if you have that problem you know you skipped this step. "

good luck!
 
" well not really, ECU is still throwing code 4 (crank angle sensor) and when i rev the engine it still only goes to 3200 rpms. wtf. "

B10 and B12 are your crank angle sensor
C1 and C2 are you Cylinder postition sensor


Did you re pin B10 and B12?

B10 is empty and you will have to add a pin, you can take it from B6 ( A/C Button if you dont have A/C ) or B7 ( unless it's a Automatic ) You will cut C1 and add it to B10, make sure you leave enough wire on C1.

B12 is a white with red stripe and you need to move C2 to it leave enough wire.

C1 you have to add a wire should be Blue/green, same with C2, should be Blue/yellow and run both wires out to the distributor.

Now make sure your distributor is wired like the Si in the pic.
 

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i used DX,STD (DPFI) -> Si,HX (MPFI) wiring

oh, my car is a manual ;)

i double checked the TPS that was the first thing i thought was wrong, but im not getting a code for that.

i have checked several times the connections at C1 and C2 and used pins from extra ECU plugs i got at the junkyard.

not sure what else there is to check. anyways..

thanks for the replies!!
 
and you made sure you distributor is wired the same as the Distributor harness plug? i'll take a look at the link.

Tps wired wrong will only make the computer think your at full throttle at idle, not give it any throttle or increase ide speed, but just dump a bunch of raw fuel in the cylinders.
 
i wired the same color wires together, like white -> white, blue/peach -> blue/peach etc.

cylinders 1 and 3 smell like raw fuel. i'll check the wiring on that again. from the instructions i used i only ran 4 wires into the engine bay; 2 for injectors 2 and 4 and 2 for the crank angle sensor in the dizzy. then i cut wires A3 and A7 and ran then to injectors 2 and 4. i used the stock red and yellow wires from the DX injectors and ran those to injectors 1 and 3.
 
ok, so ECU code 16 went away. still leaves code 4.

i know the timing is off on something, i just cant figure out what. could be three things,

-injector timing
-cam timing
-ignition timing.

i leaning towards ignition and injector timing. if the ignition was off it would fire at the wrong time (duh, lolz) and cause the unburned fuel smell. OR if it was the injector timing it is spraying fuel at the wrong time resulting in the fuel smell again.

:confused:
 
You should have run 2 wires to the injectors #3 A5 ,#4 A7 and then run 2 more wires over to the resistor box for those 2 injectors ( grounds ). Then two more wires for the distibutor C1 and C2.


"i cut wires A3 and A7 and ran then to injectors 2 and 4. i used the stock red and yellow wires from the DX injectors and ran those to injectors 1 and 3."

Is this right??? if so need to re-wire them you should of only had to add injector 3 and 4. Not any other
 
i used DX,STD (DPFI) -> Si,HX (MPFI) wiring

oh, my car is a manual ;)

i double checked the TPS that was the first thing i thought was wrong, but im not getting a code for that.

i have checked several times the connections at C1 and C2 and used pins from extra ECU plugs i got at the junkyard.

not sure what else there is to check. anyways..

thanks for the replies!!
sounds to me like the distributor wiring is not correct - if you used the diagrams from the site listed above, they are totally wrong - all of the wire colors in the DPFI harness need to match the wire colors on the Si distributor - all you need to do is add the 2 wires for the cylinder sensor - blue/green to C1 and blue/yellow to C2 - the wire locations in the Si distributor connector should be like this:

pinouts.jpg
 
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according to three different sites the wiring for the injectors is supposed to be: 1 and 3 go to stock DX and 2 and 4 go to new added wires.

so you saying this is wrong and and i should do 1 and 2 with the DX wires and 3 and 4 with the new added wires? i guess that makes more sense when reading up on this ECU pinout diagram www.fouthgenhatch.net/mpfi


jlicrx, i did wire the colors together.
 
you should of only had to add Injector 3 and injector 4. and leave injector #1 and #2 stock wiring.
 
alright, so i got the injector stuff done.

still leaves the crank angle sensor. could it be i have a third defective dizzy?? ..meh
 
the injector wiring for the MPFI is:
ECU pin A1 - to injector #1 - brown wire
ECU pin A3 - to injector #2 - red wire
ECU pin A5 - to injector #3 - light blue wire
ECU pin A7 - to injector #4 - yellow wire

at the DX ECU ECU pins A1 and A3 have a yellow wire - these wires connect together inside the harness and go to the Auxiliary injector on the DX throttle body - pins A5 and A7 have a red wire - these wires connect together inside the harness and go to the the Main injector on the DX throttle body - if you cut the yellow wire at ECU pin A3, you run a new wire from the cut wire at the ECU side to injector #2 and connect the yellow wire at the Auxiliary injector to injector #1 - if you cut the red wire at ECU pin A7, you run a new wire from the cut wire at the ECU side to injector #4 and connect the red wire from the Main injector to injector #3
 
thats exactly how i have it wired!

somewhere my crank angle sensor is not reading right. is there anything that needs to be adjusted inside the dizzy?i have tried advancing and retarding the timing but that hasnt helped any..

thanks again you guys for helping me out.
 
thats exactly how i have it wired!

somewhere my crank angle sensor is not reading right. is there anything that needs to be adjusted inside the dizzy?i have tried advancing and retarding the timing but that hasnt helped any..

thanks again you guys for helping me out.
is your camshaft timing correct?
 
i was thinking that, but how could i check that? or "fix" that?
if you didn't change camshafts or the timing belt from the way it was when it was DPFI, it should still be o.k. - i haven't seen it on OBD0 distributors, but on some aftermarket OBD1 distributors, they have the orange and white wires in the wrong location - you could try swapping the orange and white wires (the ones right in the center of the connector) and see if that fixes it - it does on the OBD1s - the white wire on the side opposite the empty hole is the igniter wire and since it runs, it is obviously in the right spot - just try switching the 2 in the center (look at picture above for crank sensor wires)
 
yeah i didnt change the cams or the timing belt or anything during this time. i'll go check in the dizzy ;)

one thought that came to me: if i had accidentally mixed up the two white wires on the dizzy (crank angle sensor and igniter) would the car run at all?
 
yeah i didnt change the cams or the timing belt or anything during this time. i'll go check in the dizzy ;)

one thought that came to me: if i had accidentally mixed up the two white wires on the dizzy (crank angle sensor and igniter) would the car run at all?
no, if you switched the 2 white wires, it wouldn't run - on the aftermarket OBD1 distributors, the orange and white wires are in the right location in the connector itself, but the other ends of the wires inside the distributor are switched - since you have aftermarket distributor, it could be the same thing - try switching them in the connector - won't hurt anything
 
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