My 1999 Jeep Cherokee sport 4.0L will not start.
I brought it to my friend who is a mechanic and he informed me the engine is getting neither fuel or spark and is most likely a computer problem, which he doesn't deal with and I should consult the dealership.
He seemed to rush to his conclusion and I figured I would consult this forum before doing anything further to see if anyone ever heard of a similar problem.

Thanks in advance!

 

If you're not getting fuel or spark then your CPS is most likely the issue.

Edit: question when you turn the key does it even try to turn over at all. Did you try starting in neutral. Do you still have electrical. Some questions to clear out other stuff

 

I do have all other electrical, besides for spark. I tried starting in nuetral and no luck. The engine cranks but will not start.

 

Crankshaft position sensor is absolutely the prime suspect. Without that input signal to the computer, you will not have spark and you will not have fuel going TO the fuel injectors, even though you may have good fuel pressure at the fuel rail.

They can be tested, but testing is not always conclusive. If you buy one, please do yourself a favor and buy a Mopar unit from a Jeep dealer. Plenty of issues with aftermarket crank sensors. Search if you want evidence.
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Here is a link to more on the crank sensor.

http://www.naxja.org/forum/showthread.php?t=1044073

 

Does the CPS have a relay or fuse associated with it that I should try first?

 

X2. OP confirmed its def the CPS and yes get OEM from dealership. It cost more but will last longer

 

No fuse or relay with the crank sensor. Direct drive....

 

So I finally got around to replacing the CPS, did it with only two bloody knuckles!
Went to fire up the jeep and no dice. Still not starting and for some reason now my gauges are not working. I also cannot hear the fuel pump working and I have no pressure at the rail.
So no spark, no fuel pressure, no gauges....

Any ideas what to check next so hopefully I don't have to have it towed to the stealership?

 

All gauges or just some of them? Here is a very quick test to help isolate this, considering that the gauge symptom just came up after you replaced the crank sensor. Unplug the crank sensor at the connector under the hood. Now turn the key to the ON position and see if the gauges work again.

If the gauges do work with the crank sensor out of circuit, the problem is still on the crank sensor circuit. Wiring/shorted sensor, etc. And yes, you can get a bad crank sensor out of the box; where did you purchase it at?

 

I don't want to tell you where I purchased it........

Ebay....It was cheap. Thought I would do a cheap one first to make sure it was the problem. But I will try what you say. Thanks!

 

You probably got a bad cps. I have heard of many people getting bad cps's when the get the cheap ones. I must say I went the cheap way and also picked one up from e-bay for $12. I must be one of the luck few. So far I've had it in for 2 1/2 years. But I do know when it does go out I'll be buying the new from the dealer.

 

With this cps problem, should I hear me fuel pump run when I try to start? right now I do not hear the fuel pump when I try to start.

 

So i just did the test with my ohmeter. Set to 20K the newly installed cps gets a reading of 3.5 between b and c terminals while my old cps got a reading of 11.9
Does this tell anyone anything?
I also disconnected the cps and still didn't have any gauges.

 

Any thoughts?

 

Ebay engine management sensors are generally bad news (unless the brand name is confirmed) so you could have a bad sensor.

But that doesn't answer the reason as to why the gauges now don't work even when you disconnect the crank sensor. If the gauges worked before the new crank sensor was installed, that is quite strange.