'90 xj - cranks but won't start

it does crank, but will not start. it's getting fuel. it is not getting spark. i changed the crank sensor, new battery, changed cap and rotor, and had the ignition coil and module checked out. i'm not sure where to go from here. it did start up a couple of days ago, ran for about 15 seconds and then died. i heard a click after it died. i assume it was the starter relay. it wouldn't start back up. any help would be great!

what about teh ballast resistor?

what's that? where is it located?

it is a 3" ling ceramic piece with 2 wires going to it it sits on the inner drives side fender behind the air cleaner box, check for good cnnections and power to it. It is the most common problem with the renix system

thanks, i check that out!

The ballast resistor is for the fuel pump, so it won't cause no-spark problems. A bad ballast resistor will allow it to start then shut down when you return the key to run position.

Have you checked the camshaft position sensor in the distributor?

no, i haven't. how do you check it?