Once the alarm is completely out and all the wiring harnesses are restored back to stock, then focus on the CPS and wiring going from it to the PCM and make sure it's getting the voltage it needs, a good ground, and the signal return wire isn't shorted or open. Next check to make sure the injectors are actually spraying the fuel into the cylinder.
Like everyone said, if you have spark and fuel in the cylinder then something should happen. If you really can't figure it out, I'd get a timing light or something and making sure the spark on each cylinder is happening when it's suppose to be and is consistant.

 

Ok, update. Got a fuel pressure tester, pump runs right at 49 psi like it says in service repair manual.
I got a scope that has the has a line that goes across the screen. Used it to see if injected work, yes they do.
I was left with spark. The coil gets 5 volts and stays at 5 volts, doesn't got from zero to twelve volts. That power source comes from the pcm the bk/grey wire.
The second wire is gr/orange which seems to be the same wire to investors and some sensors.

 

well i figured it out' it was the coil'
i thought i would check for spark one more time' pulled a plug and checked' no spark' so i put the spark plug on the coil wire and there was spark' but a lot weaker than when i first checked it out. but thought maybe my new cap was no good. i checked for resistance and it was good. based on what i have been told at garages and other mechanics and via internet, the coil either works or doesnt. but my coil was weak. at first when my durango was not running there was lots of spark at the time' but i think i was just lucky to catch it when it was working.
my pcm didnt throw any codes reguarding the coil, but noticed the engine light flashed 12 times. today we found out on the internet that the flashing engine light means 2 things' cat problems or major misfire in ignition.
i put in a new coil. and soon as i turned the key and turned the motor over, it started'

thanks to everyone who has helped me out'

 

That's good to know you got it fixed but now you're saying there was no spark. If you told us there was no spark in the first place this could have been a lot easier to pinpoint the cause.

Please excuse my ignorance but am I missing something here..?

 

There was spark in the beginning, we used a tester on the sparkplug wire and it was. Working at the time. We even used a sparkplug where we had it connected and grounded to the nearest ground to see if there was visual confirmation of spark, and there was at the time. I had put in new wires, sparkplug,cap and rotor, cam sensor, crank sensor, and kept the battery fully charged. And I still had spark 3 weeks ago. Back then I think the coil was strong enough to show spark. So we thought there was other issues and continued at that time to test other things, check wiring etc. Then yesterday we got the engine light flashing 12 times, internet research told us it may mean multiple misfire. This time there was no spark at the sparkplug, but spark of the coil wire. This lead me to believe that the coil was weak. I took a chance andd bought a new one. Problem solved.

 

Sounds good, glad to hear you got your D back on the road. Those coils will slowly fade/burn out once they get shorted out or overloaded, or sometimes are just defective, all it is is an inverter. There is a way to test the resistance of the primary and secondary coils inside it with a multimeter to see if it's bad or not.

For anyone wondering how to test it here's how:
First of all there's 2 diffrent coil manufaturers, but the resistances are so close it probably doesn't even matter, you'll most likely be the in the range of both with a good coil. The 2 manufacturers are Diamond and Toyodenso (denso). These thresholds are measured at 70-80 degrees F.
The Diamond primary resistance is 0.97 - 1.18 ohms. The secondary resistance is 11,300 - 15,300 ohms.
The Denso primary resistance is 0.95 - 1.20 ohms. The secondary resistance is 11,300 - 13,300 ohms.

Hope that helps anyone in the future diagnose their coil.

 

Thanks for updating the thread!

Glad you got it fixed.