No spark from jeep 4.0 ignition coil put new engine in got power to coil but no ground

fuses are always first.
you said no power to the coil that means 12vdc power.
so hows car run with no power to coil no electric power?
ok, seems its , running good, then you lose engine power (not usage of word engine) then you find loss of 12vdc power to the ignition coil
you blew a fuse.
1987, carb engine
no engine stated, making any spark help near impossible
2.5L Vin H, TBI injection
4.2.L Vin C, 2bbl carb.
apples and oranges different (huge difference)

the 4.2 liter gets power from a ballast resistor.
on the yellow wire . the igntion switch feeds the this resistor
the green wire, goes to the ignition module.
this wire reads 12v key on, then when cranked, or running
the module grounds the green wire for about 5/1000s of second
and then release this ground making Inductive spark (Tesla action)
. that is how the 4.2 works.

so what engine.?? some have 4.0 engine. so???

checked power the ignition coil should be a gr/or wire or so, its a 6cyl so the coil shoule have 4 wires, the rest is the coil driver wires which provide ground, connect one end of test light to power and probe the coil connector circuits.ligtdeal

Pull off the coil ignition cable at the distributor and check for spark coming out of coil when cranking engine over. Use a heavy rag or glove to hold the wire 1/4 inch from a metal ground. Should see a strong blue spark when cranking to verify ignition is good. If no spark, check for battery voltage to coil on the coil primary. If you have current to the coil, suspect a bad coil, ignition module, crank position sensor, or cam position sensor, or pcm. The coil, ignition module, and sensors can be tested before replacing.

try a new coil.some times a new coil will fail

I take it that it cranks over but will not start. Spray some starter fluid into the throttle body. If it runs, you have a fuel problem. You may have disconnected the fuel system by unplugging a connector or grounding a wire blowing a fuse.

Yes it is very much possible.But there are many other possibilities too,including starter and spark plugs issue.

If your engine cranks normally but will not start because it has no spark, or it stalls and won't restart because it has no spark.

You can also do a test to confirm the problem .The procedure to do the test is as follows:---

If your engine has spark plug wires, disconnect one of the plug wires from a spark plug and place the end of the wire near a metal surface on the engine. Then insert a small Phillips screwdriver into the end of the wire (the plug boot), or a small bolt or nail to provide a conductive path. Then crank the engine and look for a spark to jump from the screwdriver, bolt or nail in the end of the plug wire to the engine. If you do not see a spark, there is an ignition problem.

OR-----------

If your engine has a coil-on-plug ignition system with no plug wires, In that case remove one of the coils from the spark plug and insert an old spark plug, a spark plug tester or a screwdriver into the end of the coil. Ground the spark plug or plug tester to the engine, then crank the engine and look for a spark. No spark indicates an ignition problem.If the engine has no spark, check for voltage at the coil positive terminal when the ignition key is on. If NO voltage, then problem is on the trigger side of the coil (pickup, crank sensor, ignition module or primary wiring circuit).

But If there is NO voltage at the coil itself, then in that case the problem is on the supply side (the ignition switch or ignition wiring circuit).-----------------

Jeep cranks but no start:----------------

A jeep that cranks over but doesn't start, in many cases will be due to a bad fuel pump, a broken timing belt, an inoperative cam sensor or crank sensor. Also these problems are related to faulty spark plug. Check the spark at spark plugs when you start the jeep. Do you notice any spark. Actually you should see. If in case there is no spark then it's a spark plug problem. Also the coil pack gives power to spark plug. So check the voltage at coil pack. It will show 12 volt. If there is no voltage noticed at coil pack then its faulty coil pack that has to be replaced. If all the possible options checked out ok then check the car starter. The starter gets power from battery to start the jeep. If the starter is faulty then it will not let the car to start. Also check and confirm that there is fuel in the jeep. If its very low fuel then in some cases this causes the problem. Also check and confirm that fuel pump is functioning properly and the fuel filter is not clogged. One of the easiest ways to check for a fuel pump related problem is to spray a little starting fluid into the air intake while trying to start the jeep. If the car starts momentarily, then there's a good chance the fuel pump is not working or the jeep is out of gas. You can also listen for the fuel pump's humming sound when the key is first turned on. Also if a inoperative fuel pump is suspected, a good technician will always check to verify there is power and ground being supplied to the pump, to eliminate the possibility of a bad relay or electrical issue. Fuel pressure can be checked with a pressure gauge and if there is pressure, pulse can be checked at the fuel injectors in several ways including the most common, with the use of noid lights. If the injectors don't have pulse the engine won't start. ---------- This troubleshooting tips will help you to solve the problem. Thanks. Helpmech.

the crankshaft position sensor located between flywheel and trans is where the power source for the coil comes from. I suggest you need change that

did you change the computer controlls too

It would be great if you could find the Ignition Control Module!!! From my experience on my Jeep...90 YJ 4.2 liter carb. it does not have one...Computer controlled only...

If you have a 12 volt test light put the point on the positive lead to
the coil and the ground lead to a good ground ( Negitive side of battery ). Then turn the key on. If the test light comes on then you have power to the coil. With power to the coil confirmed have someone crank the engine and put the test light on the negitive side of the coil. The light should flash at a rapid steady rate. If not then your pickup in the distributor may be bad. If no power to coil with key on or when cranking you may have a bad ignition switch.
Another way to test for spark is to remove the coil wire from the dist cap and hold the end close to a ground ( 1/4 inch away) and
have some one crank the engine. If you get a good spark but no
spark to the spark plugs you may have a cracked dist cap or a bad rotor. If no spark at coil wire use a wire in place of the coil wire to check for spark. You may have a bad coil wire. Good luck. Neil W.