not getting any spark at plugs

88 xj 4x4 auto w/air
list of all new parts in the last couple of months
tps,cps,cap and rotor,plugs,ing module and coil,fuel pump and filter new vac hose assembly high $$$,alternator,batt checks good,
ran good for a while now not getting any spark at the plugs
some days it will start some it wont. also changed the camshaft sensor inside the dist cap and reset timing

HELP!!!!!!!!!!!!!!!!!!

Jeepers. You've replaced about everything connected with a no-start condition.
You might try cleaning and tightening the ground connection on the passenger side of the engine block.

Also make sure of a secure connection at the CPS plug-in connector.

I had this same problem on my ZJ a little while back, it turned out to the the Crankshaft Position Sensor. Check that one.

Take your main computer connections apart. ( the plastic box above the brake booster) Drivers side.

Fill that thing full of brake parts cleaner, spray it out with air. May want to take a small wire brush to the connections to clean them up a bit.

Repeat several times, until there is no varnish on them.

Pack full with fresh di-electric grease.

Put it back together.

Enjoy.