Injector Issues / Noid Light Tested

[Brix]

Hi All,
I have a 2002 3.7L Liberty with what I believe to be injector issues (P0202,0204,0206,0171) runs OK just gets around 10MPG. Since the codes show cylinder problems all on one side of the engine, I believe it to be an electrical issue with the passenger side injectors.
To determine this I went to autozone and bought the injector testing noid light kit. The kit has a GM noid light that matches well with the Jeep's injector so I used that. When the engine starts and for 30 seconds after the engine is running the noid light flashes (tested injectors on both sides of the engine). After 30 seconds the light stops flashing. So a couple questions.

1.) Are the noid lights supposed to stop flashing after a certain amount of time?
2.) What would cause the light to stop flashing (is it from a low quality or mismatched noid light)?
3.) Has anybody experienced the same issue with terrible gas mileage?

P.S. - Replaced the spark plugs too and found that the plugs I pulled out on the passenger side were not black and sooty, like the ones from the drivers side had been.

 

[tjkj2002]

The PCM will cut power to that injector(thus the noid light will stop flashing) after about 30 seconds or so on a misfiring cylinder that you just caused.

 

[Brix]

So that would indicate plugged injectors then?

 

[tjkj2002]

So that would indicate plugged injectors then?

No that means you caused the PCM to shut down that injector pulse after it caused a misfire from having the injector unplugged to plug in the noid light.

 

[Brix]

Not real helpful Tjkj. I'm aware that unplugging the injector would cause a misfire but that doesn't help me solve the problem.
Since the noid is flashing, it is not an electrical issue but an issue within the injectors themselves. Does that make sense?