So I completed a d16y8 swap in a classic mini and it has been running pretty great until yesterday. It’s a situation where I have fuel and spark but no fire. Timing is fine Its jus that the Injectors are not getting grounded pulse. I did install a new d series tucked wiring setup from wire Worx to keep things clean and simple. So I have spent the better part of 2 days going over all my wiring and have a couple questions:

on pinouts A1 A2 A3 A5 are the wires that send the grounded signal to the injectors. I have 12v at those wires. Shouldn’t they be grounded at 0 volts? Can someone clue me in where these wires would be getting 12v from?

What creates the grounded pulse signal?

if anyone has any diagrams I would greatly appreciate it. All I have are ECUs pinouts and the wiring to the injectors. It’s probably all very simple but I’m getting frustrated and I need to drive the car back to Atlanta from here in NJ.

thanks in advance
MikeB

 

the injectors have 12v on one side and the ECU on the other. If the ECU is not pulling it's side to ground you will read 12V. (or if the pulses are short enough for your meter to skip)
the only time you would read 0V would be if the injector is full on (ie never)

since you are running a custom harness, we are going to have trouble helping you with wire colors.

 

The wire colors and locations are factory correct. The thing I’m trying to understand is this: I understand the one side of the injectors is the relayed hot 12v side. The brown red yellow and blue wires back to the ecu are the grounded pulse wires. My meter is reading 12v on the wires at the ECUs and the voltage fluctuates when cranking. I assume this is the grounded pulse but I imagined that the voltage on this side would be less and the pulses would fluctuate to zero volts.
Am I correct in thinking that the ecu is what tells the injectors to pulse but wouldn’t be able to if it didn’t have proper grounding at A23 A24 and B(don’t remember but it’s the only black wire on the b plug)

thanks again guys. I’ve been reading all I can to get this figured out. I’m new to the Honda scene.

MikeB

 

Absolutely correct, if you have an OBD1 ECU (see below).

Otherwise, for an OBD2A or OBD2B ECU, the ECU pin numbers are different.

 

Thanks muellersfan. I will get back on this in the morning.

 

Ok. So the car is now running but it is skipping and running pig rich. The injectors are all working as per the screw driver on the injector sound test. When pulling the plugs they all look ok but cylinder 3 seems to be a little bit darker then the other cylinders. Could this still be a grounding issue and if so where should I be grounding what to what OR what should I be putting my multimeter on to verify things are correct?
Thanks in advance once again.
MikeB

 

Did you compare spark brightness between all 4 plugs using a spare properly gapped spark plug?
Have you compression tested all 4 cylinders?