I'm heading to the junkyard soon (it's 9:30a, EST) to see what parts I can find for a DPFI to MPFI swap. From my search here and every other forum, these are questions I'd like answered:

1. Does the complete IM (TGB, fuel rail, injectors & plugs, all sensors, hoses), ECU, resistor box and distributor have to be from an 89-91 si or can I use one from any D-series engine that is MPFI?

2. I don't believe I need a complete engine harness right as I can just extend wires and such from my DX harness?

3. Anything else I need?

Thanks in advance for all your help!!

progress

 

Here is the write up I used it worked perfect
http://crf50.no-ip.com/fourthgenhatch/mpfi.html

 

if your car is a 90-91 try and get an ecu from that year of car because if the ecu is 88-89 you will always get code 20. not a big issue still works just annoying having a constant code. im pretty sure it doesnt matter what year the rest of the parts come off of though. you dont need the full harness all you really need is the plugs for the dizzy but you dont have to have it. just looks better. im also not sure if you can use parts of a non si mpfi car but you probably could since its all the same.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by janz3n &raquo;</TD></TR><TR><TD CLASS="quote">if your car is a 90-91 try and get an ecu from that year of car because if the ecu is 88-89 you will always get code 20. not a big issue still works just annoying having a constant code. im pretty sure it doesnt matter what year the rest of the parts come off of though. you dont need the full harness all you really need is the plugs for the dizzy but you dont have to have it. just looks better. im also not sure if you can use parts of a non si mpfi car but you probably could since its all the same. </TD></TR></TABLE>

My car is a 90, and I have an ecu out of an 89 Si. Yet to get any code, and it is running strong

Also the BEST thing to do is just grab the complete engine harness out of an SI, and then cut and paste as needed when you have both harnesses next to each other. Any mpfi part from an 88-91 civic will work, hell you could even use the intake mani from an HF I just wouldnt recommend it.

 

why would you take out the whole harness when all you need to do is run 4 wires to the engine?

 

You dont have to take the harness out, but I really dont see how you are going to run them neatly and in-line with your old harness without doing so. It isnt like the job is extremely hard, but i think saying "all you have to do is run 4 wires" makes it sound easier than it is. I think you forgot the whole section where you have to reroute existing wires, soder and add the resistorbox.

 

is there something special about the 88 resistor box that is different than the 89-91?

nvm, same part number.

oh did i mention i have one for sale?

 

After spending several hours at the junkyard, all I got were some H center caps, an overflow reservoir and a funky sunglass tan! I did see about 4 molested 1st gen CRXs though but in terms of stuff for an MPFI swap...nada. zip, nothing, blank. Thanks for the help though. It looks like I may be getting some stuff from the classifieds here instead so all is (hopefully) good.

 

ya if you want your wiring to look neat then take the harness out but it is really easy to just run 4 wires to the engine hook up two to your dizzy, then two to #3 and 4 injectors i think i forget, then hook up your old injector wires to the other two injectors then hook up the rest of the injector wires to the resistor box. <TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Floored &raquo;</TD></TR><TR><TD CLASS="quote">You dont have to take the harness out, but I really dont see how you are going to run them neatly and in-line with your old harness without doing so. It isnt like the job is extremely hard, but i think saying "all you have to do is run 4 wires" makes it sound easier than it is. I think you forgot the whole section where you have to reroute existing wires, soder and add the resistorbox.
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the wiring is the easiest part of the whole swap in my opinion..