Dead injector output?
09-10-2023, 01:55 PM
#1
Newb
Thread Starter
Join Date: Oct 2018
Location: Seattle
Posts: 33
Total Cats: 3
Dead injector output?
I'm going to try to keep this short, but I'm super frustrated so please bear with me.
I have a 94 Miata running MS3PNP. Everything was working fine. I decided I wanted to experiment with EBC. I connected a MAC pneumatic valve to the loose 12 volt output that is often used for a timing light, and used one of the unused wires that goes from the diagnostic connector to the ECU (white/green) to connect back to the Megasqurt. I cut the wire at the underhood connector to connect to the MAC valve, and cut the white/green wire at the ECU connector and connected it to the high current 2 output on the MS options connector. I was able to test the valve successfully using the I/O test screen. However, when I started the car, it was only running on 3 cylinders. I traced the problem to cylinder 2, and using the injector test screen, I verified the Megasquirt is not firing injector D, which is for cylinder 2. I tested continuity on both wires of the injector from the connector at the injector all the way to the ECU connector. Good continuity all the way through. And I didn't touch any of the injector wires anyway. They are all in connector #2 at the ECU, and the diagnostic plug wire I cut was from connector #1. I also swapped the physical injectors between cylinders 1 and 2, just in case the injector randomly went bad. The problem stayed in cylinder 2, it didn't follow the injector.
I first thought there might be a conflict between high current output #2 and injector D, so I changed the boost control to use high current #3, also moving the wire in the options connector. No change of course. I also just cleared all of the boost control settings from the tune, and even loaded up an old tune to try to get back to a good running state. It didn't work, which makes sense, because I would think that even if I messed something up in the tune, the injector test screen should be able to fire the injector, right? I also reconnected the white/green wire at the ECU and unplugged the MAC valve from both the 12 volt and white/green wire under the hood - essentially putting the wiring back the way it was before I had changed anything. Nothing works.
Did I somehow fry the Megasquirt when installing/testing the EBC? Did I do something wrong?
I have a 94 Miata running MS3PNP. Everything was working fine. I decided I wanted to experiment with EBC. I connected a MAC pneumatic valve to the loose 12 volt output that is often used for a timing light, and used one of the unused wires that goes from the diagnostic connector to the ECU (white/green) to connect back to the Megasqurt. I cut the wire at the underhood connector to connect to the MAC valve, and cut the white/green wire at the ECU connector and connected it to the high current 2 output on the MS options connector. I was able to test the valve successfully using the I/O test screen. However, when I started the car, it was only running on 3 cylinders. I traced the problem to cylinder 2, and using the injector test screen, I verified the Megasquirt is not firing injector D, which is for cylinder 2. I tested continuity on both wires of the injector from the connector at the injector all the way to the ECU connector. Good continuity all the way through. And I didn't touch any of the injector wires anyway. They are all in connector #2 at the ECU, and the diagnostic plug wire I cut was from connector #1. I also swapped the physical injectors between cylinders 1 and 2, just in case the injector randomly went bad. The problem stayed in cylinder 2, it didn't follow the injector.
I first thought there might be a conflict between high current output #2 and injector D, so I changed the boost control to use high current #3, also moving the wire in the options connector. No change of course. I also just cleared all of the boost control settings from the tune, and even loaded up an old tune to try to get back to a good running state. It didn't work, which makes sense, because I would think that even if I messed something up in the tune, the injector test screen should be able to fire the injector, right? I also reconnected the white/green wire at the ECU and unplugged the MAC valve from both the 12 volt and white/green wire under the hood - essentially putting the wiring back the way it was before I had changed anything. Nothing works.
Did I somehow fry the Megasquirt when installing/testing the EBC? Did I do something wrong?
Reply
0
0
Thread
Thread Starter
Forum
Replies
Last Post
_spyder
Engine Performance
3
05-28-2011 12:34 PM
