weird I have spark and fuel but no start

so im lookin at a xj for a friend it just wont start it has fuel and spark i just timed it and still nothing????? but here's the kiker it has an alarm and I didn't know it at first but it was going off i noticed that on of the blinkers was on and didn't think any thing of it but then i found that the siren was un hooked i hooked it up and its going off and it started geting colder and dark so i stoped messing with it. i have never mesed with an alarm so i have no idea whare to start i think this may have something to do with my problem thow. any ideas help thanks

It could be the alarm preventing it from starting but that usually prevents it from doing just about anything. Since it's cranking, has fire and fuel sounds kinda like the CPS is bad which will almost always cause this kind of problem.

bad cps=no spark.He has spark.
If you still suspect th cps do an ohms test on it and post back the values.....

Are you sure you have the dist. indexed right?

What year/engine XJ are you looking at? What do you mean when you say you just timed it?
Is the spark a strong snapping "blue" spark or is it orange? Quality of spark is important to ignition.
Blue=Good Orange=Bad

Have you tried starting it by spraying a shot of starting fluid into the intake? If it starts or at least fires
with the fluid, you have a fuel delivery problem of some sort. If it doesn't fire, then I'd go back to looking
at spark/ignition. Try testing the primary/secondary resistances of the ignition coil with a meter.

With spark and fuel, it would almost have to be a timing issue.
Unless...The alarm has a kill relay that was used to cut the "run" portion of the ignition system, instead of the "start". In that case, the engine would crank, and just as it begins to fire and you let go of the key, the run setting would be dead and the engine would shut right down. Just like in older cars when the coil ballast resister would burn out. Are you getting something like this, or does it just crank and not even try to fire?

dont start cutting wires on the alarm. The main power should be fused under the dash, just pull the fuse. There should be a momentary push switch near the alarm also that will disarm it. put the key in the ignition and turn it on then hold down the switch with the ignition on and it should disarm.

sorry to be vauge im working on a 88 xlj with a 4.0 the problem is no start at all but im geeting orange spark but i kina figured it would at least fire. what does the orange/blue spark mean. also i found the alarm box and just unpluged it. the chick that owns this heep does not have the key fob so i had no way of disarming the alarm.

orange spark is a sign of a weak coil.....