My truck was running and stopped as if the key was turned off. checked for spark at #1 plug there was none. checked for spark from coil there was none. replaced coil checked spark at plug still none. replaced ing. mod. checked for spark at plug still none. Waht clould the problem be?

africa car? or australia? where? cars are NO THE SAME on all of earth, not ever. in fact
so country is first and year next, both not told so we go to generic answers, , ga
1:fuses bad, check them all
2: no park on all spark plugs or just one, a tech checks them all. first.
if one is bad, then the spark coil for is bad. .
there are 3 evolutions of spark for 30 years.(we cant guess yours)
1: one coil spark and a distributor
2: the paired coil packs 1pack runs 2 plugs.
3: COPS, 1 coil per plug COILS over PLUGS
what you have there I can not guess nor will i answer for all 3 technologies. now.
or post photo showing spark plugs ?

so need to find out if you have a spark or a fuel problem. do you hear the fuel pump when you turn the key. checking for spark is a matter of pulling a boot of 1 of the spark plugs and use an old spark plug and lay it on the engine so you don't get shocked when you have someone try turning the key. if you see spark over and over. I would suspect the fuel being the issue or something broke. did it run fine when you turned it off last.

check all fuses first, every time, something fails EFI.
the scan tool will tell you why 90 % of time.
connect scan tool
key on
crank for 5 seconds, see scan tool show 300 RPM? about.
good, no RPM is bad sensor (Cmp or ckp)
release key , do not turn off yet
see DTCs stored, now, bingo, its telling you what is bad. OMG.
p0340/ 355? and the like? are bad CMP, bad CKP, or others get em
post em or look them up in the FSM. or at alldata.com
Theory:
the ECU creates spark
there are the 2 sensors that tell the ECU when to spark (inputs)
and the ECU DRIVER the ignition IGNOTOR, that runs the ignition coil.
1 coil or 6 coils. depends on year.
4.0L I6 Jeep engines.


did you check for spark directly at the 1 coil car or at all 6 coils for 6 cop coil cars?

cops are coil over park plug, i think your car is 1 coil, had a 99 jeep.
and this old six still had one, coil, so does this one coil make spark
to a test spark plug, Y/N
if yes, the dizzy cap is bad or wired wrong. to plugs.
I no spark here, do the DTC scans above.!!!!!
post back results.

check the battery in the key and the engine immobiliser for operation

Check timing belt first. Some engines are interference types, such that when belt fails pistons may hit the valves causing major damage. Google search you engine # to see if your is or is not one of these. If non-interference type, you will just need to replace the belt, but most folks also replace the belt tensioner and perhaps water pump if it is also belt driven. You normally buy a kit of all these parts.

Check for spark at one of the plugs. If none, then check spark at the coil. While cranking, coil pos should light a 12 vvolt test light, and it should flash rapidly on coil neg. Also try spraying carb cleaner in the intake while cranking, but be careful. If you run into the no spark situation, an ignition module is the most likely cause.

Try this...

You need to check for spark at the number 1 spark plug if no spark then it could be a few things
1.crank shaft position sensor
2. distributor cap or plugs
3. pick up coil inside distributor
4. ignition coil
5.ignition module
6.Blowen fuse check both engine fuses and inside cab fuses
7. oil pressure switch
You can pull the coil wire going into the distributor cap and check for spark there if no spark there then your problem will be from the ignition coil back

neither ,think its the immobilisor,could be the pick up transponder behind the shroud on the ignition ,or your key has been in pocket with the mobile phone

YOUR CAR ONLY HAS COIL PACKS. CHECK VOLTAGE AT HARNNESS, IF OK REMOVE COIL PACK FROM SPARK PLUG REMOVE BOOT CHECK FOR VOLTAGE THERE, IF NONE POSS. COIL PACK.

Sounds like your starter is going out once you replace your starter your truck run better