i have a 97 cherokee and sometimes when i let it sit for a day or two it wont start. i sometimes have to dissconnect the battery and then it starts or i even disconnect the battery and the cps and it will start. can a cps work and then not work???

 

is it cranking and trying to start? Or is it doing nothing?

And yes CPS issues can be intermittent (and usually are)

 

its usually first start up of the day and after its been sitting. it sometimes cranks and does nothing and sometimes wants to start

 

sounds like a fuel delivery issue to me, do you hear the pump prime when you turn the key? How's the fuel pressure at the rail? You may have a clogged/bad fuel pump or a clogged fuel filter.

It could very well be your CPS, but i don't think so, CPS isn't affected by you letting it sit or disconnecting the battery, and would randomly shut off the vehicle also.

 

the fuel pump primes yes. when im cranking the engine it and then i stop u can smell and see smoke coming from the intake.

 

If its trying to crank over, then your are getting a signal from the CPS. Have you checked for spark? Have your checked under the distributing cap for corrosion and wear?

 

cap and rotor are 2 weeks old. im not sure how to check spark to be honest.

 

i took the sensor out 2 weeks ago when this started to happen and i cleaned it and it started right up if that helps

 

disable the fuel pump and pull each plug (one at a time) while cranking the engine, and look for a spark.

if you are getting smoke from the intake, your timing is getting off somehow, causing the valves to not close at the right time. I'm betting that your CAMSHAFT position sensor is going bad. That would be my first stop. Crankshaft position sensor would be my second stop.

 

im by myself right now and i live with my 70 year old grandpa and hes not gunna help so is there any way to do this myself?

 

yup grab some tools and so a few searches for writeups on this site.

 

i looked at the cap and rotor they look fine. i also looked at the cam sensor and it looks like its in good shape the contacts are clean.

 

bump

 

so there is fuel at the rail. and it cranks over but wont start. like i said earlier usually i could get it to start but today i cant. im guessing my crank sensor finally went dead

 

If the cam sensor looks ok, swap out the crank sensor for a new one and see if it solves your problem. Note that this can be a huge PITA to swap out (I let a mechanic sweat over mine when it went bad after i spent a few hours on my back trying to get it changed), but if you are so inclined to try it yourself...

This write-up is fantastic, and i wish i had found it when i had my issues:
http://greatlakesxj.activeboard.com/...picID=24211453