I posted this in the other Civic forum but I didn't get any replies so I thought I'd try here...

I've got an '88 civic that somebody put a D15B7 from a '93in.

Anyway, when they swapped in this D15B7 they left off the MPFI that came with it and used the DPFI equipment from whatever D15 came with the '88. Guess that's one reason it runs like shit.

Question is: I just got my hands on the MPFI intake/TB etc. from another D15b7 and am trying to figure out what I need to make it work. This isn't exactly a standard DPFI-MPFI swap like I've been reading about in this forum and others.
I'm really needing to get this engine back to the MPFI setup it originally came with and I'm not sure where to start.

I know I need the ECU & harness from a '93 or similar D15B7, will an ECU/harness out of an automatic work or do I need one from a STD car? How in the hell am I supposed to splice this into the body controls/instrument cluster from my '88?

- signing off with a stress headache

 

so do you need to run a 1993 dx ecu or a 88-91 si ecu?

 

you need to use the engine harness that came with the car, not the engine, and make the necessary DPFI to MPFI wiring changes to it - you can convert the engine to run with an OBD0 ECU (like PM6) in which case you need the OBD0 distributor or you can convert the car over to OBD1 and use the OBD1 ECU from the B7, using OBD1 distributor and an OBD0 to OBD1 jumper harness at the ECU - easier to stay OBD0

 

I think I've got to use the OBD1 ECU with the MPFI, the OBD0 ECU only has 2 injector drivers... right?

 

since the car was DPFI, it doesn't have wiring in the cabin harness going to the firewall for the extra 2 injectors nor the 2 wires for the Cylinder Sensor in the distributor - this is the wiring that needs to be added to your DPFI engine harness to convert it from DPFI to MPFI - you will need to do this regardless of whether you run it OBD0 or OBD1 - once you have done that, you will have the necessary wiring and can use the OBD0 PM6 ECU from the 88-91 Si along with OBD0 distributor - going to OBD1 will require that you purchase the OBD0 to OBD1 jumper harness that allows you to plug the cabin wiring harness into the OBD1 ECU and you would need to wire up the 4 wire O2 sensor - if this was a VTEC engine, then i would strongly recommend converting it to OBD1, but since it is non-VTEC, then OBD0 will work fine - as long as you use the OBD1 injectors from the B7, you won't need an injector resistor box - pretty simple to stay OBD0

 

I've been poring over the wiring diagrams and pinouts for the DPFI PM5 that's in my car and the MPFI P06 that's in my (potential) donor car. Making my own harness adapter to convert to OBDI seems pretty straightforward, move wires around etc. just lots of time. I also understand that I need to run the extra wires for the 2 new injectors and the CYL sensor.


Which ECU will give better performance, the OBD0 PM6 from the Si or the OBD1 P06 from the '93 DX? Is there even a difference in the fuel map?

The PM5 I'm looking at has pins for an Atmospheric Pressure Sensor, which I cannot find on the P06. Did they do away with the APS for the P06/PM6?

PM5 also has pins for a device called an "ELD Unit" which I can't find on the P06 either. Did they do away with the "ELD Unit" (whatever the hell that is) on the P06/PM6?

On the OBD0 harness (PM5) I also show a "Ignition Timing Adjust Connector" that uses the Grn/Wht supply voltage wire for the TPS, Intake Temp, Coolant Temp, and does something before going back into the ECU. What does that thing do? I can't find anything similar on my OBD1 (P06) harness.


I'm so close to finishing the research part of this project I can smell it.... It smells like.... solder fumes.

-rp

 

on the 88-91 OBD0 cars with PM5, PM6, etc. the atmospheric Pressure Sensor (PA) was located under the dash on the passenger side kick panel - on the 92-95 OBD1 cars with P06, etc., the PA sensor is inside the ECU

the ELD or Electric Load Detector is located in the Main underhood fuse box on both the OBD0 and OBD1 cars - on OBD0 ECU the pinout is at B19 and on OBD1 ECU it is at pin D10

green/white wire are ground wires - the connector is under the dash on the passenger side behind the kick panel on the 92-95 cars - its function is to disable the ECUs ability to adjust the timing while you are manually setting the ignition timing

making your own jumper for OBD0 to OBD1 is not all that simple - the OBD0 ECU plugs will not plug into the OBD1 ECU - you will need the plugs from inside of the OBD0 ECU in order to plug the cabin harness into it and you will need the plugs from an OBD1 cabin harness so that you can plug them into the ECU - you then wire between the 2 sets of plugs

 

Okay I see that now, dunno how I didn't notice D10 last night.

Cool, how do I disable ECU timing adjust to time the OBD1 motor?


I'm pretty sure I can get that done...


How about the difference between the two ECU's? Not taking into account the wiring job, do you like the P06 or PM6?