5.2 dakota ,fresh tune up won't start,plugs gap 0.40,new wires,cap,and rotor,

sounds like either the spark plugs weren't gapped right or the wires are in the wrong locations.
Google search the firing order and check the wires/loactions first, then if they are correct, have a look at the spark plug gaps.

I would look into replacing the coil even though it is sending spark it might not be enough and I would go through and just double check all my wires as well as the firing order because if it's off just a little it will make the car run rough

does that mean it CRANKS robustly, if not? fix no crank or post that.
1994 trooper. (not starting wide open throttle to clear flooding>?)
is the 4JG2 is a 3.1 L (3,059 cc), EFI engine. V6.
this is 1 of 9 engines , used,
i think this 3.1 has a distributor ,
so does the cap off, rotor spin cranking, if not , the cam chain snapped.
next, is spark (i do compression first, but im odd that way, on old iron)
i check spark. i check it to all 6 cylinders using the time honored system. we all know, right>? with a fresh test spark plug, gapped correctly. got spark.
are you spark plugs old , never did the 60k mile tune ups, (repeats)
if the spark parts are old ,no car runs right.
you know the ,ole' cap,rotor,wires , sparks filters deal.'
the we check fueling.
i look at the spark tips, are the dry,? i try the test fuel test.
if car runs for 3 seconds on test fuel the engine fuel system is dead.
check fuel pressure next.


watch scotty do his magic.

http://www.youtube.com/watch?v=064Ilsz8Fzg&NR=1&feature=fvwp

Are you sure your rotor is pushed down on the shaft correctly?

Computer box it is.

I would try making sure spark plug wires are put on in the correct firing order. This is a common mistake in tune ups. Most intake manifolds have the firinging order cast in. Plug gaps correct? I cant come too far away.

Check codes or wires on FUEL INJECTORS after i purchased a jeep that ran same motor in my case the two wires going to fuel i jector was cracked and cuased ans issues but this with everything check when changing rotor you didnt demage and wires... Depending how its runing then shutting dowone can guess chrck wiring with TBS disconnect batt to rrset computer check all power lines to ecu if thry habe fuse link wires they may look fine but actual be disconnected.. Us proper tools to ensure power going to thr ecu.. Any fuel injection connection been disconnected in error... Meed more detail to give beyer answer.. Check code map sensor or crank sensor bit more than likely when doing tune up of the rotor something got disconnected or demaged take out spark plugs may be dirty grease oil on end of plug when installing can also cause this problem... Take your time CHECK FUEL LINE PRESEURE IF TOO LOW FUEL PUMP IS BAD... ALOT OF CHEEP tool sets on ebay to check fuel lone pressure air, fuel and spark everything else is sensors ecu engine management again possibly demaged, dirty or not gap new plug or demaged wire on ignition coil or distributor or fuel injector wires or tbs wires all meed checking and ecu power supply wires that often are FUSED LINK wires tested with gauge... Good luck i am sure you will find the issue.with patients.... Doesnt hurt to double check book in firing order year to l year can make a difference.. Even if same engine

you said you repl dist cap that means you don't have a crank sensor you have electronic ing module. remove your elec ing module have it tested most auto parts stores could test your module, or check your coil at the neg terminal. should have power. if not you lost your primary volt from your batt.your secondary power is coming from your electronic ing module from the module to the pos terminal on the coil, when the eng cranks,from the coil to the dist cap , from the dist cap center to the rotor then out to the plugs,this all happen pervided the timing belt or timing chain is ok. the cumbustion chainber needs 3 things , thats fuel, air, and spark.

you need to get a diaghram on the firing order of your spark plug

wires, almost any autoparts store will give you the firing order for

your vehicle. if the firing order is incorrect the engine can sound

like its falling apart. the spark plugs also need to be gapped

correctly, they are not always pre-gapped or check the gap of

one of your old spark plugs and match the gap with the new ones.

good luck!