Home 
Home Search search Menu menu Not logged in - Login | Register
> Jensen Healey & Jensen GT Tech > Ignition > Misfire after 30 minutes

 Moderated by: Greg Fletcher Page:  First Page Previous Page  1  2   
New Topic Reply Printer Friendly
Misfire after 30 minutes  Rating:  Rating
AuthorPost
 Posted: 05-11-2016 01:53 pm
  PM Quote Reply
21st Post
UKJames
Member
 

Joined: 04-24-2014
Location: Berkshire, United Kingdom
Posts: 43
Status: 
Offline
You mentioned the coil is too hot to hold for any period of time, either there is increased resistance in the circuit (plugs/gaps, dizzy cap gaps, lead starting to beakdown) or the coil resistance has gone to pot. I've got a lucas gold and it gets a slightly warm, max. Have you tried swapping the coil out?

Last edited on 05-11-2016 01:54 pm by UKJames

Back To Top PM Quote Reply  

 Posted: 05-11-2016 02:00 pm
  PM Quote Reply
22nd Post
subwoofer
Member
 

Joined: 04-01-2008
Location: Sandefjord, Norway
Posts: 617
Status: 
Offline
60 degrees after 45 minutes shouldn't be an issue, the inlet manifold was much hotter.

Back To Top PM Quote Reply

 Posted: 05-21-2016 09:57 am
  PM Quote Reply
23rd Post
subwoofer
Member
 

Joined: 04-01-2008
Location: Sandefjord, Norway
Posts: 617
Status: 
Offline
Back from an hour mixed-traffic testing, not a misfire in sight after replacing rotor and dizzy cap with fresh (and rivet-less) items. Grand sum total for fix: 16£

HAPPY!

--
Joachim

Back To Top PM Quote Reply  

 Posted: 05-21-2016 10:19 am
  PM Quote Reply
24th Post
UKJames
Member
 

Joined: 04-24-2014
Location: Berkshire, United Kingdom
Posts: 43
Status: 
Offline
The cheap fixes are always the most satisfying! Glad you got it sorted.

Back To Top PM Quote Reply

 Posted: 06-05-2016 10:39 am
  PM Quote Reply
25th Post
subwoofer
Member
 

Joined: 04-01-2008
Location: Sandefjord, Norway
Posts: 617
Status: 
Offline
Still working and rapidly building confidence, not scared of city traffic anymore.
The more I think about it, the more likely is it that the problem was building ever since I installed the engine. Really happy that it looks like it's fixed.

Has anyone rebuilt a Smiths voltage gauge, btw? Mine is reading all over the place.

--
Joachim

Back To Top PM Quote Reply  

 Posted: 06-05-2016 09:35 pm
  PM Quote Reply
26th Post
gmgiltd
Member
 

Joined: 07-10-2012
Location: Whitehills , United Kingdom
Posts: 168
Status: 
Offline
No idea about reconditioning the gauge or even where you would source parts if they were needed. New ones are availability from Merlin in the UK if you are stuck.
https://www.merlinmotorsport.co.uk/p/smiths-classic-voltmeter-gauge-52mm-diameter-cb-v
Gordon

Back To Top PM Quote Reply

 Posted: 06-06-2016 08:47 am
  PM Quote Reply
27th Post
UKJames
Member
 

Joined: 04-24-2014
Location: Berkshire, United Kingdom
Posts: 43
Status: 
Offline
I've not delved into the inner workings of a volt gauge but have managed to bring back to life the tach and fuel sender, it is probably a fairly simple mechanism, a good clean and reassembly may well do the trick?

Back To Top PM Quote Reply  

 Posted: 06-06-2016 07:37 pm
  PM Quote Reply
28th Post
Tom Bradley
Member
 

Joined: 07-15-2013
Location:  
Posts: 200
Status: 
Offline
Before replacing or rebuilding the voltage gauge, you might want to check the ground connections on the back of the instrument panel. Loose connections turned out to be the problem back when I had jumpy gauges. The way the ground was connected on mine was pretty sloppy and unreliable.

Back To Top PM Quote Reply

 Posted: 06-06-2016 07:44 pm
  PM Quote Reply
29th Post
subwoofer
Member
 

Joined: 04-01-2008
Location: Sandefjord, Norway
Posts: 617
Status: 
Offline
Doesn't sound unlikely, actually. It seems to read right right after starting up, reading 1-1.5V low after a while.

Edit: missing half a sentence

--
Joachim

Last edited on 06-06-2016 08:17 pm by subwoofer

Back To Top PM Quote Reply  

 Posted: 06-06-2016 07:57 pm
  PM Quote Reply
30th Post
answerman
Member
 

Joined: 09-10-2012
Location: Little Chute, Wisconsin USA
Posts: 435
Status: 
Offline
I don't think there is much that even can be rebuilt on the gauge. For what it's worth, I do have one I pulled out of my bits car. I can test it to see how it reads and if it passes, I'm sure we can work something out.

Back To Top PM Quote Reply

 Posted: 06-06-2016 08:20 pm
  PM Quote Reply
31st Post
subwoofer
Member
 

Joined: 04-01-2008
Location: Sandefjord, Norway
Posts: 617
Status: 
Offline
Not really a priority, knowing it reads wrong after a while is ok, may look into it after rewiring the car, or it may have to give up the space for an oil temp gauge instead. Much more useful info really.

Back To Top PM Quote Reply  

 Posted: 06-12-2019 03:43 pm
  PM Quote Reply
32nd Post
subwoofer
Member
 

Joined: 04-01-2008
Location: Sandefjord, Norway
Posts: 617
Status: 
Offline
Finally got to the bottom of the misfire problem, it did reoccur but only after quite some time driving. It would idle just fine, then suddenly give up the ghost and die, just as if it was a fueling issue.

The solution was simple, again cheap, again ignition related. I won't get into details, but I suddenly saw my timing light go dark when it stumbled. Turns out the Pertronix Ignitor-II has an undervoltage lockout feature, so the ignition module was actually shutting down at idle as the module warmed up. Connected as per instructions (red wire to + on coil) the voltage drop through the ignition switch, tach, crummy old wiring, compounded by the hotter coil was enough that it would just go into shutdown when the rpms were low enough that the alternator wasn't really charging. One misfire or stumble could be all it took.

I really think I solved it this time.

Back To Top PM Quote Reply

Current time is 04:06 am Page:  First Page Previous Page  1  2     
> Jensen Healey & Jensen GT Tech > Ignition > Misfire after 30 minutes Top




UltraBB 1.172 Copyright © 2007-2011 Data 1 Systems