99 cougar 2.0 won't start

I have a 99 cougar 2.0 5spd and it will not start. I bought the car with a bad engine. it had thrown two rods but it would still start up. i bought a used motor from oreilly auto parts that was tested before given to me. we swaped them out and it will not start now. since that i've replaced crank sensor, cam sensor, spark plugs and wires, coil, oil change w/filter, fuel filter, water pump, thermostat, and air filters. YET IT STILL WONT START. i'm getting fire to the coil but not to the plugs.what else would cause no spark to plugs? Can someone help me with this?

What do you mean the cam sensor is sending a signal to the coil or the coil fires on top but doesn't get to the plug. I would check that the plug wires go to the correct plugs. Did you connect the grounds right kick panel behind left headlamp. I think you didn't plug in something. This is a common problem when installing motors. Double check all work on the wiring harness.

What do you mean the cam sensor is sending a signal to the coil or the coil fires on top but doesn't get to the plug. I would check that the plug wires go to the correct plugs. Did you connect the grounds right kick panel behind left headlamp. I think you didn't plug in something. This is a common problem when installing motors. Double check all work on the wiring harness.
I rechecked everything, i even took the whole wiring harness out and put it back in, i checked to make sure all grounds were good, and still no fire. what the problem is - the coil is not giving spark to the plugs nothing will come from the coil, i tried the original one from the old motor(which started before any work was done) i tried the coil that came with the used motor and nothin, I then got a brand new one and still nothing. I'm up for any suggestions.

If you have a 12 volt test light hook it up to the coil neg. see if it blinks when you are trying to start the car. They used to have a ground by the computer in the right kick panel which if loose the computer wouldn't start the car.
Three computer grounds left side of engine compartment on fender apron.
Camshaft sensor ground left side of engine on engine mount. This would be easy to miss. Fuel pump lower center rear of luggage compt. Check park/neutral switch top of transacle or clutch pedal switch top of clutch pedal.Pcm power relay left front of vehicle near fog lamp. Under battery tray.
Behind power steering column.
As you only changed the engine the parts should work 99% of the time it is something you missed I've had to go over my work 3 or 4 times hunting something. It is almost a missed ground or something unplugged. Anti freeze is a good insulator and you have to use contact cleaner on some connections.

i've rechecked everything, all grounds etc. i got the test light checked to to see if the coil would light it up and nothing. would the coolant temp. sensor have anything to do with it, thats probably one of the only sensors i havent changed out.

Check the fuses for the system. Feel the relays for the ignition and pcm power relay,and fuel pump relay do they click. Hold your finger on them, you can feel them when somebody else try's to start the car. Next use an ohm meter and put both leads on the camshaft sensor. It should go from zero to one when somebody is cranking the car. Next do the same thing to the crankshaft sensor. I got 3 bad modules in a row for a car I was working on once. If the two sensors are working clean the connectord with electrical cleaner. If you have an electrical diagram ohm the wires from the sensors to the computer. I've used a gem clip plugged into the connector and a long copper wire its takes two to do this. If you don't have a diagram unplug at the computer and use a straight pin to pierce the wire up about six inchs. ohm between the end and pin. Usually they are bad around the connector. If you have to splice get another connector at the yard and try to go up into the harness. Walmart has some connectors with a sealant on the ends for this. They are a tapered bar with a point the wire goes around the bar and the connector screws on making a good connection. To check the coil make sure you are getting 12 volt to the coil. I would ohm these wires back to the computer if you have a diagram. If not with the computer unplugged use a straight pin and ohm about six inchs. Coat where you used the pin with silicon.
Unplug the coil use an alligator clip and put 12 volt on the coil positive. Check the voltage on the neg. it should be close to 12 volt.
It justs seems odd that replacing an engine using the same good sensors that it won't fire unless a connector got damaged or antifreeze on it, and all grounds were hooked up properly.
Also ohm the plug wires.