hi!
When I bought my HF,I wanted two things:
A fully working MPGuino
and a still "intact-uncut" harness.
And long story short,after a little pulling my hair out,etc I got it figured out!
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This is here to help other people that want what I wanted,I know I can't be the only one..
So here it is,vehicle in question..
Behold,1990 CRX HF totally stock minus JDM D15B shortblock.
290k(and counting,
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)
Now let's get to the good stuff,this is your ECU.Hidden under a panel underneath the passenger's feet closest to the firewall.Held in with 4 10mm nuts,carefully pull back the carpet,and you'll see it.This is also useful for OBD purposes but we'll get to that later...Voila,here she is in all her OBD-0 glory
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Notice mine has those wires coming out,that corner of the panel is lifted up and has one screw left out?There's a reason for that.I decided to solder directly to my ECU pin's VS cutting into my harness.The reason?IMO it's wayy easier to replace a ECU VS replacing a entire harness in the absolute worst case scenario things went 'haywire,and I've seen them for sale as little as $25 online..
Let's get to the basics,a MPGuino,needs 4 things:
Injector feed
VSS (aka Speed Sensor)
Positive wire
Ground
I decided to go right here for my Injector feed.
And for the VSS,I went to pin B18 is it?
Here's a PM8 pin-out for reference
http://cx4fwq.bay.livefilestore.com/...u3/pinout2.jpg
And for my positive wire,I went through the fuse panel and found a 'empty' fuse that wasn't used for anything and just used a spade connector,it's nice and solid it fits just like a fuse would.
For my Ground I did this,it's by the upper-right side of the fuse-box, nice solid mounting point as well.
Hopefully at this point,you've got a Guino that will now turn-on and register your speed-pulses but needs the correct "settings",and this also show's how I mounted mine.I tried the 4x2x1 box from the 'Shack' and honestly it was such a pain to adapt over I threw it away,haha.Double-sided tape works just fine,as long as you have the good quality stuff.
Press the three buttons all at once to enter the settings menu.
VSS Pulses:
Microsec/Gallon:
Now I know I left some things out,but this covers the 'jist' of it.