Cylinder 4 Injector not Firing

[SnowB0und]

Got my swap running pretty good, except for a dead miss on cylinder 4. I checked and #4 injector isn't firing. So I thought I'd switch it and all would be well. That was not the case, still not firing. I checked it by taking the injector harness off and cycling injector #4 with a 9v battery and it will click. I've checked voltage on both sides of it when the key is in position 2 and get 12 v on both sides so I know the connection between the injector and harness is good. I've also checked the resistance of all of them and there all the same. ~16 ohms on a warm motor. Then I checked all of the injector signal wires to the computer connector and they are all good. So I'm at a loss, what can cause the computer to not fire the injector? I did have a missing ground on the ignition coils when I first got it wired up. I'm wondering if I fried the computer? I also had c104 miss wired not sure if that could have messed with it. Other than the injector not firing it runs great.

Any ideas?

[SnowB0und]

I was thinking about it more, I have another DME and it still misses on cylinder 4. I should take it apart and check continuity between the DME and injector just to make sure its making it through the connector.

[Three3sheaven]

I was running on 5 cylinders right after I swapped in my 24v. I pushed on top of the injector wiring cover in different places around the suspected injector and it would start firing if I pushed in a certain spot. Turned out to be not plugged in all the way. I know it sounds stupid but it looked like it was in all the way but it wasn't clicked fully and that fixed it. Putting the end of a long flathead against the injectors and putting the handle up to your ear helped me so much during this process to hear the clicking of the injector opening or not

[SnowB0und]

So I've tried that and got 12 v to both sides of the injector. That would diagnose the connection on the actual injector correct.

I also checked voltage on the signal side set to VAC and they all get a reading except #4

[SnowB0und]

I checked continuity between the DME side of the injector to the DME and it checks out good. Any ideas?

[SnowB0und]

So in case anyone finds this later. If you try to start your M/S50 with out your coil ground hooked up you can fry your DME. Both of my DME's failed on the #4 injector. New one fixed it.

[M3PO]

I was going to say DME but the fact that you had two fail on cylinder 4 threw me off!

[SnowB0und]

My guess was the coils were looking for a ground and found it through the same spot.