no start - Page 3 - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Grand Cherokee & Commander Forums > ZJ Grand Cherokee Forum > no start

Introducing MONSTALINER™ UV Permanent DIY Roll On Bed LineToxic Brakes - 3000 PSI Braided Stainless Steel Brake LineCess Recovery Gear Snatch Tow Strap OffRoad @ ROCKRIDGE4WD

Reply
Unread 02-23-2013, 08:53 AM   #31
ZeeJay1997
Registered User
1997 ZJ 
 
Join Date: Dec 2008
Location: Sweet Home, Alabama
Posts: 6,195
Quote:
Originally Posted by 715raccing View Post
Please overlook my interrupting your conversation.
That's why they call this a forum Good to have constructive input. Some of us like to troubleshoot until a confirmed problem is found. Some choose to stop and punt.

ZeeJay1997 is offline   Reply With Quote
Unread 02-23-2013, 02:24 PM   #32
PaYj
Registered User
1988 YJ Wrangler 
 
Join Date: Aug 2011
Location: Barnesville, Pa
Posts: 50
Quote:
Originally Posted by 715raccing
Please overlook my interrupting your conversation.
I had a similar condition and went through all of the agony you're experiencing only to find that the used computer I installed was the problem.The original quit and the replacement was defective too.
No interruption at all, I am really starting to believe its the PCM. I just want to cover all the bases before I throw a couple
Hundred dollar part at it and it be something stupid like a shorter wire or something.

Zee ok that was something I was unsure of was if PCM used both ckp and cps to fire the coil or not. I'm going to head out and do some quick checks before I have to go to work
__________________
78 J10 360 V8
88 Yj 305 V8 SOA
96 Zj 3.5
PaYj is offline   Reply With Quote
Unread 02-23-2013, 04:14 PM   #33
xrunndonex
Registered User
1994 ZJ 
 
Join Date: Dec 2012
Location: coffeyville, Kansas
Posts: 1,666
Quote:
Originally Posted by PaYj View Post

No interruption at all, I am really starting to believe its the PCM. I just want to cover all the bases before I throw a couple
Hundred dollar part at it and it be something stupid like a shorter wire or something.

Zee ok that was something I was unsure of was if PCM used both ckp and cps to fire the coil or not. I'm going to head out and do some quick checks before I have to go to work
I don't think it's the pcm
xrunndonex is offline   Reply With Quote
Unread 02-24-2013, 05:05 AM   #34
PaYj
Registered User
1988 YJ Wrangler 
 
Join Date: Aug 2011
Location: Barnesville, Pa
Posts: 50
And may I ask why you think it's not the PCM?? I understand you can get a bad sensor sometimes but to get a bad crank and cam sensor at same time?? I have 5v supply today I will check 5v output, I didn't have anyone to turn the vehicle over for me yesterday, but have my grandfather today when I wake up for work so will check it then
__________________
78 J10 360 V8
88 Yj 305 V8 SOA
96 Zj 3.5
PaYj is offline   Reply With Quote
Unread 02-24-2013, 12:43 PM   #35
xrunndonex
Registered User
1994 ZJ 
 
Join Date: Dec 2012
Location: coffeyville, Kansas
Posts: 1,666
Quote:
Originally Posted by PaYj View Post
And may I ask why you think it's not the PCM?? I understand you can get a bad sensor sometimes but to get a bad crank and cam sensor at same time?? I have 5v supply today I will check 5v output, I didn't have anyone to turn the vehicle over for me yesterday, but have my grandfather today when I wake up for work so will check it then
cause It's alot of money lol for something that you don't know forsure
xrunndonex is offline   Reply With Quote
Unread 02-24-2013, 03:46 PM   #36
PaYj
Registered User
1988 YJ Wrangler 
 
Join Date: Aug 2011
Location: Barnesville, Pa
Posts: 50
Ok so I check sensor ground which is good, and ckp pulse, got nothing now weird thing is when I went to check cam it went right to 5v so I thought ok it's just in that window, so I cranked it and it staye at 5 volts. I'm sorta of Monday and Tuesday so I am going to pull the inspection cover for trans just to make sure everything is ok before I go and buy another crank position sensor.
__________________
78 J10 360 V8
88 Yj 305 V8 SOA
96 Zj 3.5
PaYj is offline   Reply With Quote
Unread 02-24-2013, 03:55 PM   #37
Speedymcracer01
Registered User
 
Join Date: Feb 2013
Posts: 663
Quote:
Originally Posted by PaYj View Post
Ok so I check sensor ground which is good, and ckp pulse, got nothing now weird thing is when I went to check cam it went right to 5v so I thought ok it's just in that window, so I cranked it and it staye at 5 volts. I'm sorta of Monday and Tuesday so I am going to pull the inspection cover for trans just to make sure everything is ok before I go and buy another crank position sensor.
I had the same problem it just died on me one day and wouldn't start back up my pcm would not respond when i turn the key over no check engine light at all the over head gauges didn't work the fuel pump would stay on it wouldn't prime and stop like it should have are you having any of these problems?
Speedymcracer01 is offline   Reply With Quote
Unread 02-24-2013, 04:50 PM   #38
ZeeJay1997
Registered User
1997 ZJ 
 
Join Date: Dec 2008
Location: Sweet Home, Alabama
Posts: 6,195
Quote:
Originally Posted by PaYj View Post
and ckp pulse, got nothing
Quote:
Originally Posted by PaYj View Post
when I went to check cam it went right to 5v so I thought ok it's just in that window, so I cranked it and it staye at 5 volts.
Sound likes and open coil on cam sensor.

For grins and giggles, Disconnect all sensors on the circuit, then check for crank sensor pulse.
ZeeJay1997 is offline   Reply With Quote
Unread 02-24-2013, 05:27 PM   #39
Speedymcracer01
Registered User
 
Join Date: Feb 2013
Posts: 663
Quote:
Originally Posted by ZeeJay1997 View Post

Sound likes and open coil on cam sensor.

For grins and giggles, Disconnect all sensors on the circuit, then check for crank sensor pulse.
Have you checked the pcm fuse in the engine compartment if thats not the case check the pcm harness they are known to wiggle loose over time but alot of them never connect right again after that happens,also check the hot wire to the fuse box in the engine compartment make sure it is secure,i had a 02 sensor that was shorting out that caused momentary loss of power to the pcm it effected everything even causing the transmission to kick and loose drive i thought the damn tranny was going to drop out from under it. Then it quit on me one night and wouldn't fire back up three days later i found the naked wires on the 02 sensor was arching and poping my pcm fuse i taped the wires up and tucked them behind the heat shield sence then it has never done anything like it again. It never blew a fuse until a down tree limb pulled the sensor wires down and they wrapped around the driveshaft it rubbed the wires down to bare wires the pcm fuse would blow as soon as I would shift into any gear
Speedymcracer01 is offline   Reply With Quote
Unread 02-25-2013, 05:25 AM   #40
PaYj
Registered User
1988 YJ Wrangler 
 
Join Date: Aug 2011
Location: Barnesville, Pa
Posts: 50
I have the cel, the pump primes, I will disconnect the cam tps idle air and map sensor and check for pulse, am I missing any sensors on that circuit?
__________________
78 J10 360 V8
88 Yj 305 V8 SOA
96 Zj 3.5
PaYj is offline   Reply With Quote
Unread 02-25-2013, 08:24 AM   #41
Speedymcracer01
Registered User
 
Join Date: Feb 2013
Posts: 663
Quote:
Originally Posted by PaYj View Post
I have the cel, the pump primes, I will disconnect the cam tps idle air and map sensor and check for pulse, am I missing any sensors on that circuit?
Try your crank position sensor on top of the bell housing can be difficult to get to though
Speedymcracer01 is offline   Reply With Quote
Unread 02-25-2013, 08:29 AM   #42
Speedymcracer01
Registered User
 
Join Date: Feb 2013
Posts: 663
Quote:
Originally Posted by Speedymcracer01 View Post

Try your crank position sensor on top of the bell housing can be difficult to get to though
Either way all the sensors work together if one gives a improper signal to the pcm then thats going to screw everything up just have to keep digging and hope you find it
Speedymcracer01 is offline   Reply With Quote
Unread 02-25-2013, 09:11 AM   #43
ZeeJay1997
Registered User
1997 ZJ 
 
Join Date: Dec 2008
Location: Sweet Home, Alabama
Posts: 6,195
Quote:
Originally Posted by PaYj View Post
this all started when i was having a hard time starting in cold weather i did a tune up and found the distributor bearing was bad so i replaced it, it ran for three days like a champ and then lost spark
Have you been back in the distributor to look at the cam sensor? Knowing the sensor reference is there with the field not collapsing, it seems there is a problem there. If crank sensor starts pulsing when you disconnect it, bingo.

Circuit info from FSM:

Circuit K25 (WT/BK) splices to supply 5 volts to the camshaft
position sensor, crankshaft position sensor and
throttle position sensor.

Circuit K4 (BK/LB) splices to supply ground for the signals
from the following:
† Battery temperature sensor
† Camshaft position sensor
† Crankshaft position sensor
† Downstream heated oxygen sensor
† Engine coolant temperature sensor
† Fuel pump module
† Intake air temperature sensor
† Oil pressure sensor
† Powertrain control module
† Throttle position sensor
† Transmission solenoid assembly
† Upstream heated oxygen sensor
† Vehicle speed control switch
† Vehicle speed sensor
ZeeJay1997 is offline   Reply With Quote
Unread 02-25-2013, 09:38 AM   #44
ZeeJay1997
Registered User
1997 ZJ 
 
Join Date: Dec 2008
Location: Sweet Home, Alabama
Posts: 6,195
Be sure you have a good connection with whatever you're back pinning the signal wire with. That got me a couple of times.
ZeeJay1997 is offline   Reply With Quote
Unread 02-28-2013, 05:22 AM   #45
PaYj
Registered User
1988 YJ Wrangler 
 
Join Date: Aug 2011
Location: Barnesville, Pa
Posts: 50
Sorry no update yet, mandatory overtime. Racer if you read the post I replaced the crank position sensor twice. I am supposed to be off this weekend so hopefully I get some time to work on the jeep. Oh one update, I did take the new cam sensor out and replace it with old and I still have constant 5 volt return to PCM, what I need to do is disconnect it and see if without the sensor I have it at connector so I know if its back feeding from PCM or is it sensor itself
__________________
78 J10 360 V8
88 Yj 305 V8 SOA
96 Zj 3.5
PaYj is offline   Reply With Quote




Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.