1G One FIC injector not firing..what gives?!

[90ATEGST]

Alright everyone, I recently sent some used 1450 blue max injectors to FIC for some flow testing and they all came out pretty good. A few days ago I went to go have my car tuned (1990 Talon Tsi) and one of the injectors is not firing. Since flow testing them they had only had idle time on them. We checked spark and it is there. Checked for power at the injector clip with a noid light and it was there as well. We also jumped the injector with a 12v source manually and we could hear it pulsing, so what gives? Its just that one injector. When I put stock injectors back in the car it runs with no problems. Is there anything else that could be causing this injector not to fire?

 

[jakelandry]

I recently had the exact same issue with a set of 1450's that I sent off and were confirmed "fine" by fic. I had one that I believed wasn't firing at first, but eventually, after multiple hours playing with individual deadtimes, I found that it was firing but needed a different deadtime setting than the rest of the injectors. Almost like one just flat out wasn't a 1450. Frankly it was a huge pain in the ass. The previous owner had no issues with them, just me. I swapped out for some 2150's just cause I got a good deal on them and when I swapped I noticed my resistor pack looked pretty banged up so that's something to consider. I also had to replace the caps in my ecu so either of those could have contributed to my issue, but regardless I had the same issues and fic claimed that they were fine and just needed different deadtimes.

 

[Diamond Star Werks]

Fuel injectors fire off of a ground signal, not a 12v signal. So manually adding 12v won't do anything unless the power constant side doesn't have power. Try switching that injector to a different position. If it does it still then it's the injector if the injector that you replace it with starts acting up the it's in the harness.

 

[jakelandry]

He added 12v source with the intention of causing the injector to fire, which it did. He also said he tried his factory injectors and it ran fine so I would assume both the harness and injector are fine to some extent.

 

[boost97gst]

hose, syringe, fuel, alligator clips, and a 9v battery. Cheap and easy way to clean/test injectors. Fixed an injector on my Lincoln like that after it had been sitting for 6 months

 

[Diamond Star Werks]

He added 12v source with the intention of causing the injector to fire, which it did. He also said he tried his factory injectors and it ran fine so I would assume both the harness and injector are fine to some extent.

He also said that when he checked the harness with a noid light that it was working fine. but the injector doesn't work. But when he added power he said he could hear it pulse. Maybe he heard the other injectors unless he had a stethoscope on just that injector.
Again, injectors pulse by adding ground not power so if you add power to an injector it does nothing. if you add power to the constant side of the injector it does nothing, if you add it to the pulse side of the injector then it would make it stop pulsing. An injector is just a solenoid. I am simply noting the incorrect testing procedure he is doing.
If the stock injectors all work fine and noid light shows proper signal to the bad injector location then the injector that isn't working right has an issue in itself. Hence replace injector to resolve issue.

 

[jakelandry]

Did you physically pull the injector off and test it?