XJ XJ6 / XJR6 ( X300 ) 1995-1997

Coil / Spark help

Thread Tools
 
Search this Thread
 
  #1  
Old 04-28-2018, 04:41 PM
Lady Penelope's Avatar
Veteran Member
Thread Starter
Join Date: Apr 2017
Location: Kansas City USA
Posts: 4,039
Received 1,383 Likes on 1,087 Posts
Default Coil / Spark help

On the coils I have 12 V on the White / Pink wire but no timed grounds on the ECU it provides on the return green wires for all 6 cylinders ?

All ECU ground points provided .

The reading is 25 ohms static or rotating and in theory should be 0 and open as it sequences .

Brain not working today

I thing somehow it is immobilized of inhibited , I'm talking about the car .

Fully charged battery 12.84 v
 

Last edited by Lady Penelope; 04-28-2018 at 05:09 PM.
  #2  
Old 04-28-2018, 11:55 PM
Join Date: Feb 2014
Location: Crossroads of America
Posts: 19,389
Received 12,732 Likes on 6,377 Posts
Default

Hi Parker,

I'm tired too, but it would help to have a bigger picture of the symptoms you are diagnosing and if the onset was sudden or has been coming on for some time.

If the engine is immobilized, the engine will not start. If the engine will not start, the ECM will not trigger the coils or injectors to fire.

If the engine is running, how are you trying to measure the pulsed grounds as the ECM switches each coil on? I haven't tried this on an X300, but I would think you would need to set your meter to Duty Cycle or use an oscilloscope, but you might possibly be able to measure some voltage with your meter on the AC Voltage setting.

Have you confirmed no spark?

Sorry I don't fully understand the issues you are dealing with.

Cheers,

Don
 
  #3  
Old 04-29-2018, 06:57 AM
Qvhk's Avatar
Veteran Member
Join Date: Mar 2013
Location: Hong Kong
Posts: 1,006
Received 269 Likes on 201 Posts
Default

US versions of the X300 have no immobilizer. Could be just electrical gremlins who are disrupting the norm?
 
The following users liked this post:
Don B (04-29-2018)
  #4  
Old 04-29-2018, 12:04 PM
Join Date: Dec 2009
Location: Wise County,TX
Posts: 11,891
Received 7,878 Likes on 4,762 Posts
Default

CKPS or inertia switch????????????????

bob
 
  #5  
Old 04-29-2018, 12:55 PM
Lady Penelope's Avatar
Veteran Member
Thread Starter
Join Date: Apr 2017
Location: Kansas City USA
Posts: 4,039
Received 1,383 Likes on 1,087 Posts
Default

Originally Posted by motorcarman
CKPS or inertia switch????????????????

bob
Thanks Bob I thought of those yesterday and verified .

The engine ran 6 months ago .

With the fuel rail pressure holding steady with a solid check valve I can watch it lower as the injectors spit .

Starter fluid will not light off so I suspected ignition .

Cleaned the plugs and reoiled the cylinders for possible bore wash .

New fuel .

Power to the coils but the timed grounds are not present as I watch with a needle meter .

So I suspect the ignition is inhibited .

I think it's somewhere between the SLCU and the ECU as I was helping others out because I like to tinker .

Noticed that somehow I'm missing power on the supply side of the fuel pump relay so I jumpered power on the output side for fuel pressure . King relay in truck clicks and swaped . Battery terminal not the best bite and will replace .

My brain never woke up yesterday so I tagged out but will look at it again later .
 

Last edited by Lady Penelope; 04-29-2018 at 12:58 PM.
  #6  
Old 04-29-2018, 02:12 PM
Join Date: Feb 2014
Location: Crossroads of America
Posts: 19,389
Received 12,732 Likes on 6,377 Posts
Default

Originally Posted by Lady Penelope
The engine ran 6 months ago .

With the fuel rail pressure holding steady with a solid check valve I can watch it lower as the injectors spit .

Starter fluid will not light off so I suspected ignition .

Power to the coils but the timed grounds are not present as I watch with a needle meter .

So I suspect the ignition is inhibited .

Noticed that somehow I'm missing power on the supply side of the fuel pump relay so I jumpered power on the output side for fuel pressure . King relay in truck clicks and swaped . Battery terminal not the best bite and will replace .
Hi Parker,

I still feel like I'm not understanding the full picture, but I gather from the above that the starter motor runs and the engine cranks/turns over/rotates, but the engine will not start. It would start and run six months ago but has not been started in about six months. Is that correct?

You mentioned in your first post that the fully-charged battery measured 12.84V. Have you watched the voltage sag while cranking the engine? If the voltage falls much below 11 volts while cranking, the ECM may not trigger the ignition to fire.

I don't know if you will be able to see the pulsed grounds to the coils on a needle meter - they happen so quickly that a standard voltmeter may not be able to react to them, especially a meter with averaging/RMS type filters. I suspect that to see those pulses you will need a digital meter that can measure duty cycle or frequency or an oscilloscope. A much easier test is to pull one coil and spark plug, pop the plug in the coil and reconnect the coil to the harness. Ground the threaded sleeve of the plug with a battery jumper cable and watch for spark while you crank the engine.

You have new fuel - are you certain there was no water in the tank prior to filling with gasoline?

Cheers,

Don
 

Last edited by Don B; 04-29-2018 at 02:15 PM.
The following users liked this post:
MountainMan (04-29-2018)
  #7  
Old 04-29-2018, 02:27 PM
Lady Penelope's Avatar
Veteran Member
Thread Starter
Join Date: Apr 2017
Location: Kansas City USA
Posts: 4,039
Received 1,383 Likes on 1,087 Posts
Default

Good points with the pulse of the needle may not be seen as well as the possibility of water in the empty tank as it was emptied over the winter .

Car ran 6 month ago .

Good starter rotation .

Going to try " Hard Reset " later as I was tinkering with the SLCU wiring for someone .
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
GvilleVDP
XJ XJ6 / XJ8 / XJR ( X350 & X358 )
9
06-06-2013 08:20 AM
vjsimone
XJS ( X27 )
4
01-08-2013 06:39 PM
mike66
XK8 / XKR ( X100 )
6
05-01-2010 07:28 PM
wnlewis
XJ6 & XJ12 Series I, II & III
4
04-02-2009 10:17 PM
bigdaddywuff
S-Type / S type R Supercharged V8 ( X200 )
11
03-12-2008 09:19 PM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


Quick Reply: Coil / Spark help



All times are GMT -5. The time now is 02:05 PM.