So just to be sure, if you add fuel manually to the intake the engine will not fire and then die, right?
i.e. spray Quick Start(ether in a spray can) into the intake and crank the engine it does not fire at all
First stop would be the ignition system getting power.
Coil pack has 4 wires, red one should have 12volts(battery voltage) when Key is on.
That power comes from the EEC fuse in engine fuse box, 30 amp fuse
Next would be the CKP(crank position) sensor
On a 4.0l it is located by the crank pulley, front of the engine about 10:00-11:00
If you look down at it you will see the Tone Wheel, looks like a gear behind the pulley.
It has 35 teeth and 1 gap, missing tooth
The CKP sensor sends a pulse to the EDIS module(spark module) each time a tooth passes by it, the missing tooth, tells EDIS module when #1 is at Top Dead Center(TDC), so it can time spark and firing order.
EDIS module sends that CKP pulse to the computer so it can time fuel injectors.
So no CKP pulse = no start
You can test a CKP sensor using a Volt Meter set to AC volts, when starter motor is turning the crank the CKP sensor should generate about 1 volt AC
But also inspect the tone ring, if a tooth breaks off then there would be 2 gaps and EDIS module would not know which was TDC so would not start spark.
Thats pretty much it for spark
CKP=========EDIS Module===========Coil pack-------spark plug
EDIS module does not need the computer to start spark, just power and CKP pulse
EDIS modules rarely fail, never even read about one that failed, wiring of course could be bad.
EDIS module is usually located on the Rad support, on my '94 it is on the front side of rad support, have to look up under the bumper to see it.
Google: EDIS-6 images
To see what that module looks like
Go here: http://forums.hybridz.org/topic/4979...il-pack/page-2
Scroll down to post #27
Click on the first picture to enlarge it
That's the whole Ford spark system, EDIS-6, Coil pack, CKP sensor and tone wheel
And just as a heads up because I goof up the drivers side spark plugs wires all the time
5-6-4 side gets me every time