MPFI Swapped 90 EF hatch- Si harness

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blackice90HB

Senior Member
hey, just threw a Z6 in my 1990 Std hatch. The wiring was from the old zc, which was a 89. That explained the problem I had with the car, 89 harness was different than 90.

My hatch has alreaddy been prepped for MPFI. I got a harness coming from a 90 Crx Si, OBD-0 MPFI to OBD-1 MPFI. Question is..........once I wiring in the injectors and double check the crank sensor wiring, it should work, correct?


n00bs dont try and tell me that 88-91 are the same they are not with wiring. I just cant find a cannon plug pinout to verify it for my self.
 
you cannot use the Si engine harness in the 90 STD car - at the driver's side firewall connection to the chassis harness, the Si has a round 8-pin connector where the STD/DX has a round 14-pin connector - at the passenger side firewall connection to the chassis harness, the Si engine harness has 3 connectors where the DX chassis harness has only 2 connectors - you should use the engine harness that was on the ZC, get OBD0 to OBD1 ECU jumper, rewire the distributor for the OBD1 connectors, use the OBD0 injectors or eliminate the injector resistor box and use the OBD1 injectors and extend the wiring for the MAP sensor and cooling fan switch (need different connector)

this is the passenger side Si harness connectors:

siharness4.jpg


this is the passenger side STD/DX harness connectors:

dxpassconn.jpg
 
The harness on the ZC was FUBARed. crap. Do you know of any schematic with the pinouts on those cannon plugs? If it comes down to a nessesity I will repin the wires at the cannon plug. I just need a schematic so I know what goes where.
 
Wait, but that square plug is just for the injectors. i have already made my own harness that goes from the ECU (A1,3,5,7,15) to that square plug in your pic, thats on the same branch as the R. box.

Do you know if there are any differences in the cannon plugs itself? The only FI wires out of the STD cannon plug are the two yellow/black ones for the main/aux. injectors. If the wires are in the same location, minus the injector wires, then it should be the same thing? Would you happen to know of a schematic for the cannon plugs?
 
looking closer today, it seems that on a Si harness, the IAT sensor is in the harness with the injectors, where its not in the Dx harness. I dont have that converted harness yet, so we will see for sure when it gets in. I'll keep everyone posted.
 
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