no start

[stevodango69]

i have a 00 grand cherokee with a 4.0l in it i replaced the crank position sensor and it doesn't want to run. it will fire some times and when it does it missses really bad. other times it won't even start. took the plugs out number 3 and for cyclinder look like their not firing. changed the coil packs and no difference. could it be the crank position sensor it not spaced right it had a paper on it to set the gap figured that was right. could it be the cam position sensor. and some the gauges only work part of the time. the volt gauge doesn't work at all.

 

[Glamissand1]

with no fire, i like to work back from the piston. does the coil have power? is timing correct ( eye ball it with cap and rotor). I had a CPS go out on me, it was not a fun time. the comp needs to be reset, if u dont it wont work right. if you have a multimeter u can check all ur fuses without removing them. check the CPS connector make sure its tight and makeing good contact.

 

[stevodango69]

timing is on have spark now it runs but only for a few seconds i changed the pcm and the cam position sensor and still doesn't run

 

[Glamissand1]

does the fuel rail have high enough pressure? what is the compression of your pistons. if spark is on right then its got to br fuel or combustio.

 

[Bounty__Hunter]

Could be a bad replacement CPS, I've seen it, or a bad connection in the harness to the CPS. Both can cause rough or intermittent running.

 

[stevodango69]

nope it was the pcm