XJ6 & XJ12 Series I, II & III 1968-1992

XJ12 S2 Won't start

 
  #1  
Old 01-05-2019, 01:51 AM
Junior Member
Thread Starter
Join Date: Jul 2017
Location: Melbourne
Posts: 10
Likes: 0
Received 1 Like on 1 Post
Default XJ12 S2 Won't start

I have an XJ12 S2. It won't start, I think its something to do with the ignition system. I changed the coil and I think I may have wired it up wrong but I've tried all combinations and tried again with the original coil. The car was starting prior to this but would stall unexpectedly after driving it for little while, so someone suggested the coil may be stuffed. Anyone have any ideas on what could be wrong?
 
  #2  
Old 01-05-2019, 03:59 AM
Join Date: Feb 2010
Location: Adelaide Stralia
Posts: 19,263
Received 5,667 Likes on 4,069 Posts
Default

Oliver,

S2 V12

What year,

Carby?

Fuel Infected?

Huge difference in diagnostics, and which hundreds of pages of scribbles I have on them suckers.
 
  #3  
Old 01-06-2019, 05:27 AM
Junior Member
Thread Starter
Join Date: Jul 2017
Location: Melbourne
Posts: 10
Likes: 0
Received 1 Like on 1 Post
Default

Hi mate.
It's 1974. Carburettor engine with a Crane ignition system.
 
The following users liked this post:
Grant Francis (01-06-2019)
  #4  
Old 01-06-2019, 06:16 AM
Join Date: Feb 2010
Location: Adelaide Stralia
Posts: 19,263
Received 5,667 Likes on 4,069 Posts
Default

OK, plot thickens.

Do you have spark?
What Crane are you running, XR700, or XR3000.
Does the beast still have the vertical huge ballast on the RH side of the throttle pedestal?
Is the Tacho "jumping" slightly whilst cranking?
Where is the Crane box mounted?
 
  #5  
Old 01-09-2019, 05:33 AM
Junior Member
Thread Starter
Join Date: Jul 2017
Location: Melbourne
Posts: 10
Likes: 0
Received 1 Like on 1 Post
Default

Hi mate,

No there is no spark from the coil. I don't know what model Crane it is. Yes it has the huge ballast on the RH side of the throttle pedestal. The Tacho doesn't jump when cranking there is no movement. The Crane box is mounted at the back of the engine bay on the RH side.

Oliver
 
  #6  
Old 01-10-2019, 05:16 AM
Join Date: Feb 2010
Location: Adelaide Stralia
Posts: 19,263
Received 5,667 Likes on 4,069 Posts
Default

Originally Posted by Oliver343 View Post
Hi mate,

No there is no spark from the coil. I don't know what model Crane it is. Yes it has the huge ballast on the RH side of the throttle pedestal. The Tacho doesn't jump when cranking there is no movement. The Crane box is mounted at the back of the engine bay on the RH side.

Oliver
1) OK, dead system.
2) Should be a label on it somewhere, my bet is an XR700, but that is a pure guess.
3) OK. That ballast is fickle at best. I have a terminal schematic for that thing somewhere, and I will dig it out over the weekend.
4) OK, no pulse via that ballast, as yours has the tacho driven via that ballast, as apposed to any other system, where the tacho pulse is via the NEG (-) terminal of the Ign coil.
5) OK as long as that box is EARTHED well. I would "think" about moving it up front, top of rad support panel is where I place it, as that rear section is the HOTTEST area of the engine bay.

#1 test for now:

Ign ON, measure the volts at the POS (+) terminal of the coil. Should be somewhere around 7v. Now crank the beast, and note the volts, should be around 12v. This is a very basic test of the ballast and the system.

Next:

Trace the wire of the Crane that is the 12V Ign Feed Power wire, RED is its colour, and ensure it is NOT connected to the POS (+) of the coil. That is sooooooo common, and will only supply that box with 7v +/- and that is not enough to get the thing excited. The fitting instructions show that wire attached to the coil +ver terminal, and ALL that I have installed that way, a VERY long time ago, do NOT work until a GOOD 12v Ign ON volts is applied.

My copy of the installation booklet is attached just incase, BUT beware what I said above about that RED wire.
 
Attached Files
File Type: pdf

Last edited by Grant Francis; 01-10-2019 at 05:18 AM. Reason: spelling still sucks
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Japawels
XJ6 & XJ12 Series I, II & III
8
06-14-2018 06:01 AM
Terry007
XJ XJ12 ( X305 )
8
04-03-2017 01:15 PM
my-key
XJ6 & XJ12 Series I, II & III
41
08-25-2015 08:06 PM
awinstrom
XJ6 & XJ12 Series I, II & III
1
06-02-2008 04:15 PM

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

Thread Tools
Search this Thread
Quick Reply: XJ12 S2 Won't start


Advertising
Featured Sponsors
Vendor Directory

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: