I have a problem with an 88 Civic. I just swaped out the dual point motor for a single cam D15 VTEC, I used the original harness to convert to multi port, pluged in a PM6 from a 91 Si, there are no check engine lights or codes on the computer, but the car will not run. I checked the injectors and they are not working, however, just for the hell of it I plugged in the original PM5 ecu and the engine fired up. It ran alright, but it felt like it was running in limp mode. Can anyone help me?

 

Check your wiring. It sounds like you wired the mulipoint incorrectly.

 

I have checked the wiring 10 or 20 times already, and it all checks out. The only thing that I that I did differently is that I used OBD 1 injectors and I bypassed the resistor box because the OBD 1 injectors dont need the resistor.

 

If it ran somewhat on the pm5 ecu but not on the pm6 then maybe you have a wiring at the dizzy hooked up wrong, I know you said that you checked all the wires but the signals that tell the ecu when to fire the injectors come from the dizzy..

And its not running in limp mode, the pm5 only has 2 injectors so only injectors 2 and 4 are firing..

 

Uhh... You plugged an OBD1 motor into an OBD0 harness. What exactly are you using? The injectors & distributor from the D15B will not work on the OBD0 harness. You need to get a conversion harness and convert to OBD1 with the OBD1 injectors, distributor, and ecu. Then you'll need to wire in vtec.