the HF/Si harnesses look the same but have different pin locations for some wires.

Get a 88-91 civic/crx manual and go through the wiring diagrams.

 

i bet you anything you havent swithched the 2 white wires around..maybe thats whats causing the no spark in your car...or take it to a honda guy who knos about this type of ----...

 

HF and Si harness is the same thing (just added some plugs for EGR and stuff)

On my first swap I had the same problem, and spent 4 days tearing everything apart. Turns out the ECU ground on the thermostat housing wasnt grounding right due to some corosion and me not tightening the wire down properly...

Check to make sure your ECU is powering up and going into its initial diagnosis mode when turned on (check engine comes on for a sec or two when key in the iginition reaches on position)

 

Sorry dude, but they are NOT the same harnesses. I've done several swaps throughout the years, and I got stung one time doing one. A customer brang me a Swap for his HF, I figured I would save some time by swapping on a extra CRX SI harness on the engine we were putting in. Well, we put the engine in the HF w/ the SI harness and the thing would not start. It had like 3 or 4 different codes, I started looking at colors of wires on the main plugs and they were in fact different. We swapped the SI harness out with the HF harness (the one that came out of it) and it fired right up with no codes.

So reguardless if they are both MPFI, the pins are in different locations. IF I were you I'd swap the HF harness back on if ya still got it. Because you may run into other problems.

Jeff

 

Wellll Excuuuuuse me
I mis-read thought that he had only had an hf harness, not an si in an hf.....in that case get rid of the si harness its messing you up

When I said they were the same I meant that they accomplish the same thing and you dont need to be removing it. Hf has a bunch wierd stuff added in for EGR crap and such...

^^^
Do what he said

 

Thank you jeff I keep telling people hf/si harness is different not a soul wants to believe me. Did the same thing and came up with 2 or 3 codes I believe. Check your grounds check your grounds and if you give up on it I'll buy the car.

 

Just making sure clear info is getting to our users

 

the only difference in the hf and si harnesses that i know about is the ignitor wire, the si has it on the pass shock tower, the hf is on the drivers, you need to run the white wire from the ignitor at the dizzy to the drivers shock tower, i have a 89 hf and am using a si harness. heh i couldnt belive i had to figure this out for my self like a year and a half ago. thank god for pinouts

hope this helps
-joseph

 

Odd, I remember having like a coolant temp code, Intake air temp sensor code, TDC code and all kinds of ---- with just a crank.

 

So basically, I need to get an HF harness right? I'll see who has one first...