1998 Nissan frontier: where is the ignition coil?

did you reprogram the New ECU to the Truck ? if not there is your Problem , if crank or cam sensors fail to operate ? this truck will not crank at all , the Distributor in this year Model truck is old school mechanical type and they are the safest in market . they have internal mechanical driven pulse ignition modules if these modules fail ? you will have crank but no spark without ground short . you must Have either unprogrammed ECU ? or a wiring short in main Harness ( between power and ground ) to cause ECU to fry , Ignition non these trucks are also direct power supply with 40 Amp .
do you have the complete service Manual for it ? if not here is a gift for you : 1999 Nisan Frontier, KA 24 class
http://pdf.textfiles.com/manuals/AUTOMOBILE/NISSAN/frontier/1999-KA/ec.pdf

Here are the 3 engines listed for this year. IGNITION TIMING

2002 Nissan/Datsun Truck Frontier Pickup 2WD 2.4L SFI 4cyl

The Ignition Timing

18-22 DegreesBefore top dead center - When throttle positionsensor disconnected and using suitably programmedscan tool.When adjusting idle speed, set parking brake & chock drive wheels, curb idle speed (750-850 RPM)transmission in neutral.

IGNITION TIMING

2002 Nissan/Datsun Truck Frontier Pickup 2WD 3.3L SFI 6cyl

The Ignition Timing

8-12 DegreesBefore top dead center - throttle position sensorharness disconnected.When adjusting idle speed, set parking brake & chock drive wheels, curb idle speed (700-800 RPM)transmission in neutral.

IGNITION TIMING

2002 Nissan/Datsun Truck Frontier Pickup 2WD 3.3L SFI SC 6cyl

The Ignition Timing

8-12 DegreesBefore top dead center - throttle position sensorharness disconnected.When adjusting idle speed, set parking brake & chockdrive wheels, curb idle speed (700-800 RPM)transmission in neutral.

Sparks plugs, spark plugs wires, coils, defective battery or fusible link.
Ignition swith faulty

The ignition coil is part of the distributor assembly, weak spark will make it run bad, not a cheap part.

Ignition Control Module is the Obvious Problem here

Including filter; the oil capacity for a 2WD, 2000, Nissan, Frontier, 4cyl (Ka24de) is 3-3/4 quarts. Straight out of the Haynes manual.

Wow, that's almost as cool as the lady who's brakelights came on in the middle of the night whenever it got cold. It seems like you almost have to have a questionable connection between the battery and starter and the extra water is finishing the job. See if your engine compartment is leaking and, if it is, follow the water. Check the battery ground at the engine block.

Fuse Number 39 10amp fuse Color Red.
Fuse Number 11 10amp fuse Color Red
This illuminated your dash (cluster)

Let me know if this help you.
Check with test light.

Just a guess, but I would say this truck ran low on oil at one time. The result is the crank bearings took a beating. You may get away with just replacing the bearings and a rear seal. This engine is amost 'bullet-proof''! Frankster016

Its the distributor that needs to be replaced. Its probably the coil alone that bad but the coil is built into the distributor, so you will have to replace as one unit. Make sure when replacing the distributor you set the car in base timing thats the rotor head tointed to cylinder #1 and number on piston on TDC(topdead center)before you remove distributor shaft then repalce in the same position and your problem should be solved. Good Luck