Is replacing the cap and rotor as easy as it sounds? It seems like I'd just take em off, put the rotor back on the same as the old one was placed on, put the cap on and plug the wires up in the right firing order, correct? Also, can anyone tell me what the proper gap is on the spark plugs for a 94 cherokee 4.0 I6? I've lost my manual so idk...

 

It really is that easy. The gap is 0.035

 

Here is the firing order just in case

 

Yes, you have the cap and rotor replacement correct. There should be decal some where in the engine compartment that gives you the correct gap for your spark plugs, if not the clerk at your auto parts store should have the information that you need.

 

just do it its really easy just print out the firing order so you cant mess it up good luck

 

Well, I did it...pretty sure I did it right too...and the xj still won't start. I have no clue where to go from here. Maybe ignition coil?

 

Are you getting spark?

 

That is ALWAYS the first question when a vehicle turns over fine but doesn't start.

Pull a spark plug, keep it attached to the plug wire, place the spark plug electrode near a good engine ground, have a buddy crank the engine while you watch. You are looking for a strong, blue, snapping spark. Yellow/orange/white spark indicates a "weak" spark, which may not be strong enough to start the engine.

If you have good spark, your problem may be a fuel delivery issue but you should start by verifying SPARK.

Report back what you find.

 

I have no spark!

 

okay. Can we assume that you tested for spark??

If so, the #1 suspect is the crankshaft position sensor. The #2 suspect is the ignition coil.

Here is a link to a good thread that details how to test your crank sensor.

http://www.jeepforum.com/forum/f11/c...ailing-639123/

For testing your coil, buy a manual with the procedure. Coils are tested for both primary and secondary resistances.

You'll need a meter for testing both of the above. Buy one if you don't have one, as they are invaluable if you are doing ANY work on your XJ.

 

I did test for spark...nothing. I thought coil first but the guy down at autozone said exactly what you said...cps is most likely the cause. So, I think I tested the cps right. On my multitester I put it on the 200 Ohms setting so it reads 3 digits then a decimal. I connected the black end to the B port and the red end to the C port on the CPS. The meter read 152.34. So I think my cps must be bad right? B/c the link said it should be set on the 1k to 10k ohms reading, which I put it on first and it didnt pick up anything. And so if it is reading a solid 152 then I'd assume that is not an infinite resistance like it should be, correct?

 

Just replace it and be done with it. You must have spoke to the only Autozone employee that knows a thing or two. Ignition coils do not fail and cause a no spark condition very offten, always test for voltage and a pulsing ground at the primary side of the coil be for replacing it.

 

Ive heard bad things about Autozone's in different regions, but the Autozone's around here are very helpful and the guys at the one I frequent actually know a lot about vehicles.

 

Not the case in my area. Because they replaced a water pump on an old slant six, they think they're an expert on all that is automotive.

 

i vote cps.......autozones around my neck of the woods are to auto parts stores what burger king is to a steak house..