I have a 1990 ef with a zc block and y8 head converted to obd1 with a p28 ecu that isn’t currently chipped. Running z6 injectors. Got it running but it’s running shitty. I used a screwdriver to listen to the injectors, all are ticking except for 3rd cylinder. I got a test light and both wires have power when the key is on but not firing for some reason. All 4 injectors are brand new

 

Swap a known working injector over and see if it fires. Both wires should not have power though. The wires could be shorted to each other. Could also be a bad injector driver in the ECU

 

Both wires have power on all 4 injectors. Just one isn’t working. I’m gonna swap em tomorrow. What’s the secret to getting injectors into the fuel rail? It takes all my strength to shove them in and I’ve have 2 o rings cut. I don’t know what the issue is

 

Both wires to each injector should not have power - only the yellow/black wire should have 12V at each injector.

I use a small amount of polyurea grease on the o-rings - that should help them slide into the fuel rail. If you're having to push with all your might, you're either rolling the o-rings or they are going to get torn/cut, as you experienced.

 

There seem to be two different sized o-rings that manufacturers are using for these injectors. In my experience the "ultra-power" brand injectors (which everyone sells, basically) use o-rings that are slightly too big for my fuel rail. If you buy the fuel injector o-ring kits they'll come with 2 sizes of o-rings, and you can try both. The smaller (usually green) one usually fits. This might have to do with the 2001-2005 D series injectors using bigger fuel rail -> injector o-rings.

As for the injector not firing, I'd unplug it and jump power/ground to it and see if it clicks. If it doesn't you know it's gotta be a bad injector... otherwise... good luck.

 

Check resistance of the injectors, they should all be the same, around 11 ohms (i think) regardless, if there is one that is wildly different there is an issue.