Im about to swap my 91 dx civic's wiring to obd1 the good ole fashioned way, custom hack and re-pin job. Right now I have a y8 in it and I swapped it to mpfi a while back. Ok, Im planning on using this http://www.boosted.org/ecu/COMPLETE.txt table to wire on the new ecu plugs. Mainly what Im worried about is if this thing is accurate, and If having a DX and/or mpfi swap is going to interfere with it. Am I going to have to undo anything that I have already done? I did the MPFI swap according to what the info on the net tells you (every page with the info is the same). I dont want to run obd1 injectors, I want to use my resisitor box with my dsm injectors I have installed already. Lastly, I have my vafc hooked up right now and I would like to keep it that way. I would like to have control of my vtec and im using the afc hack for the turbo im running. Do I just leave it hooked up like it is now? Please help, thanks!
-Alex

 

Well without going too deep into this...the one thing I will give you is, that an ecu designed to operate saturated injectors cannot operate peak and holds with a resistor...it can work the other way around but not the way you propose. The reason is that saturated injectors require less amperage to operate therefore the drivers won't support peak and holds. What you will have to do is use an obd 1 ecu which has peak and hold drivers...basically a prelude or accord ecu. OBD1 circuitry is the same though for the mostpart so that won't complicate your problem too much..you'll just need to pop in a another eeprom to get your maps right. As far as the rewire goes, basically what you have done is fine in place where it is. The easiest approach to this is to basically assemble a jumper to go inbetween the in car harness and the ecu. Then you need to add your obd1 additions which are basically the electronic VSS, 4wire o2, and then some plug differences. In your jumper then you basically should do your reroutings to send all the signals to the appropriate locations.

 

So you are telling me that if i want to use my p28 without chipping it I HAVE to wire the injectors directly to the ecu?? bypassing the resistor box??

 

you dont really have to go electronic vss tho

 

so how come not everyone is changing their injectors when they obd1 swap if you have to???

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CRX_Control &raquo;</TD></TR><TR><TD CLASS="quote">you dont really have to go electronic vss tho</TD></TR></TABLE>

Any benefit of having an electrical vss?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hatchback_al &raquo;</TD></TR><TR><TD CLASS="quote">so how come not everyone is changing their injectors when they obd1 swap if you have to???</TD></TR></TABLE> Obd 1 injectors are optional. If you go with obd 1 injectors just remove the resistor box.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eda6 &raquo;</TD></TR><TR><TD CLASS="quote">

Any benefit of having an electrical vss?

Obd 1 injectors are optional. If you go with obd 1 injectors just remove the resistor box.

</TD></TR></TABLE>

si what your saying is that you can still use the obdo injectors on the p28 ecu? what about the clips for the intectors..those would have to be changed?

 

PM sent hatchback_al

 

use obd-0 injectors w/ resistor box, wired as normal.

don't forget your 4-wire o2 sensor.

look into just buying a jumper harness.. $100 or so and u can convert back to obd-0 easily (for sale of the car or what not).

 

i dont feel like spending 100 bucks on a harness, my car isnt going anywhere Permanent is ok for me. So I can install the plugs according to that link I posted and not change anything else and Ill be ok????

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RC000E &raquo;</TD></TR><TR><TD CLASS="quote">Well without going too deep into this...the one thing I will give you is, that an ecu designed to operate saturated injectors cannot operate peak and holds with a resistor...it can work the other way around but not the way you propose. The reason is that saturated injectors require less amperage to operate therefore the drivers won't support peak and holds. What you will have to do is use an obd 1 ecu which has peak and hold drivers...basically a prelude or accord ecu. OBD1 circuitry is the same though for the mostpart so that won't complicate your problem too much..you'll just need to pop in a another eeprom to get your maps right. As far as the rewire goes, basically what you have done is fine in place where it is. The easiest approach to this is to basically assemble a jumper to go inbetween the in car harness and the ecu. Then you need to add your obd1 additions which are basically the electronic VSS, 4wire o2, and then some plug differences. In your jumper then you basically should do your reroutings to send all the signals to the appropriate locations.</TD></TR></TABLE>

???? You do not need the electrical VSS. You can run the cable VSS with the OBD1 ecu/setup. IF you want to run the p/h injectors, you must keep the resistor box. If you want to run the sat injectors you must remove the resistor box and close the circuit....solder all 5 wires together. The injectors are regardless of the ecu OBD.

 

has anyone used that link i posted that can verify its all legit??

 

bump cus im gonna try it in an hour lol