I started my DIY conversion yesterday. I got the ecu obd1 plugs from the junkyard out of a auto civic (only one that had them). I googled the pinout conversion offline and everything went well except my fuel pump won't kick on. I checked the main relay wires and 3 of the 4 connect and there's one extra. The main relay wire colors are 2 yellow/blacks and 2 green/blacks. One of the green/blacks was the extra one.
I guess what I need to know is if the wires are swaped (green/black1, and green/black2 yellow/black 1, yellow black2) like yellow1 is in yellow 2 spot will it make a difference? And what do I do with the extra green black?
If I could get a known working pinout of the conversion that would be awesome so I can double check my work??
Also insted of the fuel pump kicking on I hear a humming noise kinda in the middle of the dash or the back of the block (hard to pin point) any thoughts?

Is my first Honda and my first conversion so if I made things confusing just Lmk and I can clarify. Thanks in advance!!!!

 

Underneath your back seat there is a connector. should be 4 wire connector, check there to see if you have power going to your fuel pump, if there isn't power there, than you can trace that power wire to it's power supply, My ef is fully converted to obd1 hardwired like your doing and if I recall correctly I didn't have to change anything at the main relay, check your ecu pinouts again.

 

are the wires in question at ECU pins A12, A13, A14 and A15 on the OBD0 ECU? - if so, the green/black wires at A12 and A14 come out of the ECU and splice together inside the harness and run to the #1 pin on the main relay - the yellow/black wires at A13 and A15 likewise come out of the ECU and splice together and run to the #7 pin on the main relay

the yellow/black wire at the #5 pin on the main relay runs to the fuel pump

on the MPFI cars, the yellow/black wire to the injector resistor box splices into the yellow/black that runs to pin #7 on the main relay

on the DPFI cars, the yellow/black wires for the main and auxiliary injectors splice into the yellow/black wire that runs to pin #5 on the main relay and the black/yellow wire from the EACV plugs into the yellow/black wire at the 14-pin firewall connector and this yellow/black splices into the yellow/black wire that runs to pin #7 on the main relay

on the MPFI cars the black/yellow for the EACV goes thru the passenger side connector to a jumper connector which goes to the underdash fuse box

these are the wiring diagrams for the DPFI cars:




these are the wiring diagrams for the MPFI cars:





you may notice that the pin numbers for the ECU on the above diagrams don't match what you usually think of as being the numbers - this is because Honda didn't number them like most of the other manuals, like Chilton, Haynes, etc. - this chart will show the differences:

 

I'll deffinatly check the fuel pump for power when I get home. This is the pin out conversion I used. Is everything correct or is this why things are funky? It says to take one of the yellow/blacks to pin a8 obd1 side but on the pinout I looked up for obd1 says slot 8 is empty... Why would I take a main relay to an empty slot? When I get home infront of a computer ill search some more.

If this is the right pinout for obd0 to obd1 then it has to be my wiring h
ttp://honda-tech.com/showthread.php?t=1319235

Thanks guys, just getting overwhelmed and really want to get it started tonight..

 

the link you posted appears to be correct for converting the OBD0 MPFI chassis harness to OBD1, however, it doesn't work for converting the OBD0 DPFI chassis harness to OBD1 - the DPFI harness needs to be first converted to MPFI - the chart is correct - OBD0 A14 (green/black) goes to OBD1 A8

 

Ok well I'm checkihg all connections and fuel pump right now. I'll let yall know what happens!
Thanks a lot guy!

 

Ok well i found out that i am getting no power to fuel pump.. I tested it at the pump first and then at the main relay. the main relay is getting power, ground, and ign, but its not getting a ign power at pin4 (st switch?) what does this go to and come from. Im guessing that my main relay went out, but it could be that the pin 4 st switch is not getting power so its not sending power to fuel pump? or am i wrong?

The humming noise i mentioned earlier in the post was my IACV sensor is sarting to go bad.
So now if i can just get the fuel pump to kick on ill be all set.

does anyone know what the ST Switch runs to so i can try and find out why its not getting power? is it fused or could there be a short?


Much thanks in advanced guys!!!

 

EACV sensor is going bad not IACV* still a noob lol

 

My car is a 91 crx si so its mpfi alrady. I get no power to fuel pump from main relay. I get power constant power, ground, and ignition but I don't.get st switch power with key forward. What the hell does st switch in the main relay harness go to??
All fuses are good. Ecu wiring double checked, fuel pump omes on with jummped power so it still works. A guy I work with was trying to say that my obd0 fuel pump won't work with a obd1 computer? Is that right???

 

look at the above wiring diagrams - st switch is the blue/white wire

no, that isn't right

 

this might help:

 

That's the wire I don't have voltage at. I checked the fuse and its good. Do you know where that wire runs to so I can check ot for a short? I'm also going to check the main relay to make sure its working.
Let yall know what I find out.

 

Ok well my relay is good and i just now put 2 and 2 togeather that the st switch stands for STARTER SWITCH!! so the blue white wire is only hot durring cranking. then its dead. i though it was a ign wire that stayed hot. so my relay is good and all wires in relay harness are good. all fuses are good. ground is good. what else would cause this.

also what does it mean when your Check Engine Light is solid and wont go off after 5 seconds? i checked tps for voltage and it tested out so that rules out my ecu right?

 

UPDATE:

Thnaks guys for all the help. just letting yall know that it was the ECU that was not sending sig to main relay. solid CEL was the tip off. its all good now and waiting on new HA motor chpped p28 ecu.