From what you've done so far, sounds like a computerized ignition problem, unless you're timing chain went out. The only things that would prevent spark to you're plugs would be if you're Oil Pressure Sensor is bad or a faulty/dirty R.P.M sensor.
Need more info, does it turn over? Did you check to see if you have fuel getting to the engine (does the pump in the tank run when you turn the key)? Do you have spark (check with a inline spark tester $6.00)?
The starter or solenoid are most likely bad. The starter assembly can be removed and put on a starter tester to see if its bad.
Sears
A dead weight tester is an accurate calibration source of pressure. A dead weight tester uses weight over a precisely known area to produce an accurate output pressure. Uses would be precision calibration of gauges, transmitters, switches and level devices.
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With a radiator cap pressure tester. The tool usually comes along with a cooling system pressure test kit.
That is a sound pressure level meter (SPL meter).
thats a little on the worn engine side of compression,but that in itself would not keep it from starting....most likely a fuel or spark problem. you can check fuel pressure with a screw in guage from autozone,and check spark with an inline spark tester from autozone.
get a fuel pressure tester on the fuel line going to throudle body there is a fitting looks like a valve stem twist off cap screw on the tester . hold tester so you can see it and turn key but dont start the motor if it reads below 54 pounds its bad. check with auto store on pressure to be sure im close.
I bought a wrist band type of blood pressure tester at Amazon.com. I found that they were the most reasonable.
The cooling system can be pressurized using a cooling system pressure tester. When engine is cool remove the fill cap and attach the tester, since caps are different styles on many vehicles an adapter may be needed. Pump the tester up until the maximum pressure (most caps have max psi on them) of the cooling sytem is reached. If there is a fast leak the max psi may not need to be obtained before the leak is revealed. There is a video at DenLorsTools.com in the tech article section that shows a pressure tester being used, it also has information about purging air from the cooling system after the leak has been repaired.
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