Intermittent crank no start w/ new cps, cam sensor
01-09-2018, 01:16 PM
#1
Newbie
Thread Starter
Join Date: Jan 2018
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee(SJ)
Intermittent crank no start w/ new cps, cam sensor
1998 Jeep Cherokee 4.0 4x4 234k
So I got one for y'all. I've thrown a bunch of new parts at this and had it running for a couple weeks and now I'm right back where I started. It started this morning no problem, ran great, but now it won't start. While running it does have a check engine light but my scanner is not compatible.
PO did cap, rotor, plugs and wires around 5k miles ago.
The fuel gauge and voltage gauge do not work right now, but when they do it will fire. Very rarely will it start with them "dead."
Initially I thought it was fuel related so put in a new fuel pump no dice. Tested the pressure at the rail and it's good. Checked all relays and fuses they looked good. Did replace one for the starter relay. New battery terminals and cleaned the grounds. And a brand new battery when I first bought it.
Moved onto the crank sensor still nothing. It was a Mopar too. I cleaned the NSS. Then a new starter. Then a new camshaft position sensor seemed to do the trick. That lasted for a couple weeks now I'm back to square one. Sometimes if I leave the terminals disconnected for a while the gauges work and she fires. I don't have a clue what do you guys think?
So I got one for y'all. I've thrown a bunch of new parts at this and had it running for a couple weeks and now I'm right back where I started. It started this morning no problem, ran great, but now it won't start. While running it does have a check engine light but my scanner is not compatible.
PO did cap, rotor, plugs and wires around 5k miles ago.
The fuel gauge and voltage gauge do not work right now, but when they do it will fire. Very rarely will it start with them "dead."
Initially I thought it was fuel related so put in a new fuel pump no dice. Tested the pressure at the rail and it's good. Checked all relays and fuses they looked good. Did replace one for the starter relay. New battery terminals and cleaned the grounds. And a brand new battery when I first bought it.
Moved onto the crank sensor still nothing. It was a Mopar too. I cleaned the NSS. Then a new starter. Then a new camshaft position sensor seemed to do the trick. That lasted for a couple weeks now I'm back to square one. Sometimes if I leave the terminals disconnected for a while the gauges work and she fires. I don't have a clue what do you guys think?
Last edited by StuckInParkingLot98; 01-09-2018 at 01:30 PM.
01-09-2018, 02:57 PM
#2
CF Veteran
Join Date: Nov 2017
Location: Groton, MA
Posts: 3,695
Received 234 Likes
on
207 Posts
Year: 1995
Model: Cherokee(XJ)
Engine: I6 4.0L
Did you get the 2 grounds in the trunk (drivers side behind the trim panel)? Those grounds are notorious for corroding and causing electrical hell.
You can get Autozone (or your local parts retailer) to read your CEL code for you. I'm sure that would be helpful for troubleshooting.
You can get Autozone (or your local parts retailer) to read your CEL code for you. I'm sure that would be helpful for troubleshooting.
01-09-2018, 03:28 PM
#3
Newbie
Thread Starter
Join Date: Jan 2018
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee(SJ)
Did you get the 2 grounds in the trunk (drivers side behind the trim panel)? Those grounds are notorious for corroding and causing electrical hell.
You can get Autozone (or your local parts retailer) to read your CEL code for you. I'm sure that would be helpful for troubleshooting.
You can get Autozone (or your local parts retailer) to read your CEL code for you. I'm sure that would be helpful for troubleshooting.
01-09-2018, 03:59 PM
#4
CF Veteran
Check the wiring to the crankshaft position sensor carefully. No fuel and voltage gauge combined with a no start is a classic sign of CPS circuit being bad. Could be the sensor was fine, but that the circuit in general is having an issue. Make sure to take a close look at the harness that wraps back around the fuel rail, they have a reputation for rubbing on the fuel rail and getting damaged.
By the way, that circuit having a problem also has a reputation for making it impossible for getting an obd2 scan tool to connect to the pcm.
By the way, that circuit having a problem also has a reputation for making it impossible for getting an obd2 scan tool to connect to the pcm.
01-09-2018, 04:39 PM
#5
Newbie
Thread Starter
Join Date: Jan 2018
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee(SJ)
Did you get the 2 grounds in the trunk (drivers side behind the trim panel)? Those grounds are notorious for corroding and causing electrical hell.
You can get Autozone (or your local parts retailer) to read your CEL code for you. I'm sure that would be helpful for troubleshooting.
You can get Autozone (or your local parts retailer) to read your CEL code for you. I'm sure that would be helpful for troubleshooting.
Check the wiring to the crankshaft position sensor carefully. No fuel and voltage gauge combined with a no start is a classic sign of CPS circuit being bad. Could be the sensor was fine, but that the circuit in general is having an issue. Make sure to take a close look at the harness that wraps back around the fuel rail, they have a reputation for rubbing on the fuel rail and getting damaged.
By the way, that circuit having a problem also has a reputation for making it impossible for getting an obd2 scan tool to connect to the pcm.
By the way, that circuit having a problem also has a reputation for making it impossible for getting an obd2 scan tool to connect to the pcm.
01-09-2018, 04:43 PM
#6
CF Veteran
Going to sound crazy.
My 87 (yea i know its renix)has occasional no crank issue.
I found the CPS appears to get polarized, best way i know to explain it.
I unplug it, and plug it back in and it starts every time.
Never heard of another having that issue.
owned it for 7 years and it might do it a few times a year.
My 87 (yea i know its renix)has occasional no crank issue.
I found the CPS appears to get polarized, best way i know to explain it.
I unplug it, and plug it back in and it starts every time.
Never heard of another having that issue.
owned it for 7 years and it might do it a few times a year.
Thread
Thread Starter
Forum
Replies
Last Post
allevolution
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
19
12-07-2019 01:26 PM
chevyguy1450
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
12
02-04-2014 01:28 AM
Mikeythrash
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
14
01-04-2014 10:52 PM
96ckeecntry
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
4
04-20-2013 08:09 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)