b_hoov

so i have a write-up telling me how to convert from dpfi to mpfi on my 91 hx, today i converted my plugs over to obd1 (basically cut/solder/heat shrink to eliminate the jumper harness and save myself around 120$ in the process, my concern is converting to mpfi, in the engine bay things are still wired to dpfi, but the write up i have is converting an obdo car from dpfi to mpfi, is the wiring going to be the same on obd1? as i read it (obd1 pinouts) i see...

a1- injector 1
a2- injector 4
a3- injector 2
a5- injector 3

however on my dpfi to mpfi write up it tells me to solder all of my yel/blk wires together (in the engine bay, not using a resistor box) then run two additional wires inside to the ECU to 2 different C connector pins, from what im able to gather i need to run 4 wires from my ecu, a1,a2,a3,a5 into the bay where they will conect directly to my injectors, then solder all of my yel/blk wires together and run wires from them to the other side of my injectors?!?!?!?! here is the link im using for my dpfi to mpfi conversion and the obd1 pinout diagram

http://www.angelfire.com/d20/hcivic88/dx-siwiring.html

4drEF

You should be able to hunt down 2 existing wires in the engine harness to connect 2 of the injectors. The other 2 you will need new wires for.

OBD0 DPFI
A1&A3 connect together - Yel -Aux Inj
A5&A7 connect together- Red - main injector

Your setup can use the red and yellow wire from the DPFI to run 2 injectors.

You are correct with the yellow/black wires. Just solder them together and since you aren't OBD0 just solder the other 4 wires from each injector to this.

OBD0 MPFI - FOR REFERENCE!
A1 - brn - Inj1
A3 - red - inj2
A5 - lt blu - inj3
A7 - Yel - Inj4

b_hoov

but a7 is my fpr on my p28...im just going to trace the yellow and red wires (dpfi injector wires) back to the ECU and pin them in a1 and a2 and run two add wires for the other 2, i don't think you understand the issue im having but i think i have it figured out.

Jarrat

Whoa..

Why not desolder some plugs out of a old pm5 ecu, and just the ecu plugs out of a wrecked eg and make a conversion harness...


Wouldn't have be better then hacking the crap out of your harness?

redef90si

iTrader: (3)

this is why i bought an SI

b_hoov

i just do not like the clutter of a jumper harness, not that its out in the open or anything but i just dont like them, i used one to ensure i had the wiring correct and i also used a pinout diagram i got off here to double check everything. and i put that money towards metal for my intake manifold im making

efjones9

tell me more about this...could u make a obd0-obd1 jumper harness this way??

b_hoov

^ yes you can, i started to make my own but did not, you will need an old pm5 ecu as stated, take it apart and desolder the plugs on the printed circuit board, then solder 20ga wires to all of the little prongs on the back side of the plug, then find an obd1 car and cut the male side of the harness off,and solder the wires to the wires you soldered onto the pm5 plugs, really quite simple. if you have the skill/time save yourself the $

4drEF

Understood that A7 is FPR on the OBD1. I had labeled the list with OBD0 DPFI to show you the stock wiring for your DX harness since you clipped the plugs off.

I was trying to explain that you could use 2 existing wires in the harness instead of running 4 completely new wires.

efjones9

thanx sounds like a good investment for ebay selling hahaha thanx ima try this
jus a question? how would u know to which wires go to what wen u desolder the wires from the ecu? sorry for the off subject matter lol