Trouble shooting 123 dizzy

Technical advice Q&A
User avatar

Topic author
rswaffie
Posts: 801
Joined: Sat Jul 19, 2014 7:56 am
Location: Lincolnshire
Great Britain

#1 Trouble shooting 123 dizzy

Post by rswaffie » Wed Jan 02, 2019 6:03 pm

Hi,
I’ve not been able to start my 63 fhc since it returned from having the engine fitted. It fired up and was driven off the trailer but has not been started since as I’ve been finishing off the bonnet electrics.
I’ve confirmed that there is fuel in the carbs.
I’ve checked the resistance at the primary and secondary coils in the Lucas Sports coil and they are factory spec.
There is no spark at the plugs.
There is 12v at the ignition wire to the 123 dizzy.
I’ve checked that the other wires are connected to the coil.
I suspect that the 123 has failed - can anyone suggest a way to test it in situ? Can I use a multimeter to check if there is a voltage leaving the 123 to the coil when turning the engine over?
Richard

S1 3.8 FHC Opalescent Golden Sand with Tan Trim 889504
Nearing completion of a comprehensive nut ‘n’ bolt restoration in my small, but utilitarian garage :wrench: :hammer: :fingerscrossed:

Link:
BBcode:
HTML:
Hide post links
Show post links


Tom W
Posts: 272
Joined: Sat May 05, 2018 10:18 am
Location: UK
Great Britain

#2 Re: Trouble shooting 123 dizzy

Post by Tom W » Wed Jan 02, 2019 7:02 pm

Is your car positive or negative earth? I’m assuming nothings been disconnected or changed since it last ran.

I’d look at the simple stuff first before condemning the 123. Do you have a spark if you connect a plug into the king lead? This would indicate a rotor arm or distributor cap problem? What’s the battery condition like? The 123 has a minimum and maximum operating voltage, and if the voltage drops too low whilst cranking, it might not generate a spark. I had the opposite problem when a failing alternator relay caused overcharging which then caused the 123 to cut out and misfire.
Tom
1970 S2 FHC

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

Topic author
rswaffie
Posts: 801
Joined: Sat Jul 19, 2014 7:56 am
Location: Lincolnshire
Great Britain

#3 Re: Trouble shooting 123 dizzy

Post by rswaffie » Wed Jan 02, 2019 8:12 pm

Hi Tom,
The battery is fully charged. I have checked using a spark plug tester the ht lead from the 123 and there is no spark.
In terms of what’s changed since it last ran, the bonnet plug has been connected to complete the front lighting and the reverse light has been connected.



Cheers
Richard
Richard

S1 3.8 FHC Opalescent Golden Sand with Tan Trim 889504
Nearing completion of a comprehensive nut ‘n’ bolt restoration in my small, but utilitarian garage :wrench: :hammer: :fingerscrossed:

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

mgcjag
Moderator
Posts: 4533
Joined: Fri Jul 09, 2010 6:15 pm
Location: Ludlow Shropshire
Great Britain

#4 Re: Trouble shooting 123 dizzy

Post by mgcjag » Wed Jan 02, 2019 9:02 pm

Hi Richard....have you left the ignition on at any time..it can burn out the basic 123 model.....not sure if the 123 tune is the same....also remove the cap.....look in at the center carbon....they can break up....sometimes becaus the cap is not put on properly....double check the cap can appear to be on and clips attached but very easy to not fit it on square...Steve
Steve
1969 S2 2+2 & Building a C type replica

Link:
BBcode:
HTML:
Hide post links
Show post links


Tom W
Posts: 272
Joined: Sat May 05, 2018 10:18 am
Location: UK
Great Britain

#5 Re: Trouble shooting 123 dizzy

Post by Tom W » Wed Jan 02, 2019 9:09 pm

I thought the 123 had a built in cut off to protect against the ignition being left on.
Tom
1970 S2 FHC

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

politeperson
Posts: 906
Joined: Tue Jun 07, 2016 8:26 pm
Location: Boston UK
Great Britain

#6 Re: Trouble shooting 123 dizzy

Post by politeperson » Wed Jan 02, 2019 9:55 pm

Richard,

With the ignition on and the cap off, why dont you slacken the adjustment bolt.

You can then check the green led light blinks as you rotate the distributor by hand. If you get a green light you have power to the 123 and the 123 is probably ok.

I assume you dont have a ballast resistance ignition.

I also assume you haven't powered the distributor from the oil pressure sender by mistake. The wire is close by.
James

L.J.K. Setright was right.
"You just cant beat a good E-type"

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

Topic author
rswaffie
Posts: 801
Joined: Sat Jul 19, 2014 7:56 am
Location: Lincolnshire
Great Britain

#7 Re: Trouble shooting 123 dizzy

Post by rswaffie » Wed Jan 02, 2019 10:11 pm

Thanks for the info chaps.
I will check for the green light and the condition of the centre carbon.
The ignition has been on whilst I’ve been checking other wiring circuits - not for more than 30 secs though. I’d be a bit disappointed if the 123 didn’t have some sort of protection though.
Richard

S1 3.8 FHC Opalescent Golden Sand with Tan Trim 889504
Nearing completion of a comprehensive nut ‘n’ bolt restoration in my small, but utilitarian garage :wrench: :hammer: :fingerscrossed:

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

chrisfell
Posts: 1041
Joined: Tue Oct 06, 2009 9:52 am
Location: Salisbury
St Lucia

#8 Re: Trouble shooting 123 dizzy

Post by chrisfell » Wed Jan 02, 2019 10:19 pm

Tom W wrote:
Wed Jan 02, 2019 9:09 pm
I thought the 123 had a built in cut off to protect against the ignition being left on.
Yes it does. If turns itself off after a preset interval if the engine isn’t turned over.
Chris '67 S1 2+2

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

andrewh
Posts: 2351
Joined: Fri Dec 21, 2007 8:31 am
Location: kent
Great Britain

#9 Re: Trouble shooting 123 dizzy

Post by andrewh » Wed Jan 02, 2019 10:24 pm

you will not get the 123 to produce a green light unless you follow the instructions in the 123 installation manual. One or other of the wires from the 123 needs to be disconnected from memory. Do it as per the book or else you will not get a green light. The instructions are very ambiguous to my mind and require reading a couple of times to make sure you do it correctly.
Also 123 hates bad earth and will malfunction or not function at all if you have a bad earth. Which model of 123 is it that you have fitted?
1962 3.8 Series One FHC

http://etype860897.blogspot.com/

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

mgcjag
Moderator
Posts: 4533
Joined: Fri Jul 09, 2010 6:15 pm
Location: Ludlow Shropshire
Great Britain

#10 Re: Trouble shooting 123 dizzy

Post by mgcjag » Wed Jan 02, 2019 10:24 pm

Hi Chris....re a cut off in the 123....is that on both the jag-6-r-v and tune versions......i had the jag-6 fitted on another car quite a while ago and thought i could remember that you shouldnt leave ignition on......but could well be mistaken....Steve
Steve
1969 S2 2+2 & Building a C type replica

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

Topic author
rswaffie
Posts: 801
Joined: Sat Jul 19, 2014 7:56 am
Location: Lincolnshire
Great Britain

#11 Re: Trouble shooting 123 dizzy

Post by rswaffie » Wed Jan 02, 2019 10:48 pm

Hi,
It’s the 6-r-v-pos version with 16 curves via a switch, bought from Holden’s. It’s only been fired up a few times so should be ‘as new’. I’ve checked the website and there is a cut-off.
If the weather permits, I’ll get it on the drive tomorrow and check all connections.
Richard

S1 3.8 FHC Opalescent Golden Sand with Tan Trim 889504
Nearing completion of a comprehensive nut ‘n’ bolt restoration in my small, but utilitarian garage :wrench: :hammer: :fingerscrossed:

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

Topic author
rswaffie
Posts: 801
Joined: Sat Jul 19, 2014 7:56 am
Location: Lincolnshire
Great Britain

#12 Re: Trouble shooting 123 dizzy

Post by rswaffie » Thu Jan 03, 2019 12:24 pm

Hi All,
I’ve checked all the connections and they are ok.
I’ve gone through the setup process in the instructions (removed black wire, loosened dizzy and rotated it).

No sign of a green light.

I’ve now removed it and have it hooked up to a dc power supply, with the red wire to earth. No sign of life. With 12v at the blue wire, should I expect to see 12v at the earth using a multimeter?
Richard

S1 3.8 FHC Opalescent Golden Sand with Tan Trim 889504
Nearing completion of a comprehensive nut ‘n’ bolt restoration in my small, but utilitarian garage :wrench: :hammer: :fingerscrossed:

Link:
BBcode:
HTML:
Hide post links
Show post links


Tom W
Posts: 272
Joined: Sat May 05, 2018 10:18 am
Location: UK
Great Britain

#13 Re: Trouble shooting 123 dizzy

Post by Tom W » Thu Jan 03, 2019 1:08 pm

That doesn’t sound right, check the wiring diagram here. http://www.123ignition.nl/product.phtml?id=270

Without it on the car and cranking, you won’t get it to work properly. It detects when the engine isn’t rotating, and cuts the circuit to the coil to prevent the coil burning out. Even if you rotate the distributor by hand, I’m not sure you’ll measure 12v on the black wire. The distributor intermittently connects the coil -ve terminal to the battery -ve terminal to fire the coil.

When you checked for the LED was the engine at or close to TDC on number one cyl on the firing stroke? If it was anywhere else, e.g. TDC on the exhaust stroke, or TDC on a different cylinder, the distributor will be in the wrong place to light the LED. Depending on which version you have, the LED should be timed to either TDC or an amount before TDC. It’s all a bit confusing as they don’t use a consistent value across all the versions they make, but you should be able to get it close enough to run either way.

Since you’ve taken it off, you’ll have to reset it from the start and retime the engine. This would have been set when the engine was built and installed, so it might be worth checking with the garage, so you don’t get it wrong and damage the engine.
Tom
1970 S2 FHC

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

Topic author
rswaffie
Posts: 801
Joined: Sat Jul 19, 2014 7:56 am
Location: Lincolnshire
Great Britain

#14 Re: Trouble shooting 123 dizzy

Post by rswaffie » Thu Jan 03, 2019 1:49 pm

Hi Tom,
The wiring was as per the diagram and the timing was set against 1 cylinder. It had been fine, so I would have expected that by loosening it and turning the unit the green light would have registered. I’m going to dig out my refurbished original Lucas and leads and install that for the time being. I’ve contacted the manufacturers to see if they can suggest anything.
Richard

S1 3.8 FHC Opalescent Golden Sand with Tan Trim 889504
Nearing completion of a comprehensive nut ‘n’ bolt restoration in my small, but utilitarian garage :wrench: :hammer: :fingerscrossed:

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

Topic author
rswaffie
Posts: 801
Joined: Sat Jul 19, 2014 7:56 am
Location: Lincolnshire
Great Britain

#15 Re: Trouble shooting 123 dizzy

Post by rswaffie » Fri Jan 11, 2019 5:33 pm

It looks like the 123 distributor Has blown its power board as the manufacturers have had to replace it. They have suggested I check the voltage from the alternator. This was a brand new Powerlite dynator- is it likely to be faulty? What’s the best way to check the output?
Richard

S1 3.8 FHC Opalescent Golden Sand with Tan Trim 889504
Nearing completion of a comprehensive nut ‘n’ bolt restoration in my small, but utilitarian garage :wrench: :hammer: :fingerscrossed:

Link:
BBcode:
HTML:
Hide post links
Show post links


JagWaugh
Posts: 559
Joined: Sat Sep 21, 2013 12:56 pm
Location: Eglisau, Switzerland
Switzerland

#16 Re: Trouble shooting 123 dizzy

Post by JagWaugh » Fri Jan 11, 2019 6:00 pm

You can put a voltmeter on it to see if it's putting out too many Volts, but that won't tell you if it's noisy. To see the noise you'd need a scope.

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

Topic author
rswaffie
Posts: 801
Joined: Sat Jul 19, 2014 7:56 am
Location: Lincolnshire
Great Britain

#17 Re: Trouble shooting 123 dizzy

Post by rswaffie » Fri Jan 11, 2019 6:14 pm

Thanks Jagwaugh, I’ve got a voltmeter. Is it a case of hooking it up to the dynator and turning the engine over on the starter?
Richard

S1 3.8 FHC Opalescent Golden Sand with Tan Trim 889504
Nearing completion of a comprehensive nut ‘n’ bolt restoration in my small, but utilitarian garage :wrench: :hammer: :fingerscrossed:

Link:
BBcode:
HTML:
Hide post links
Show post links


JagWaugh
Posts: 559
Joined: Sat Sep 21, 2013 12:56 pm
Location: Eglisau, Switzerland
Switzerland

#18 Re: Trouble shooting 123 dizzy

Post by JagWaugh » Fri Jan 11, 2019 6:27 pm

The simple test is put your voltmeter between "+" and earth and measure the battery voltage with the engine turned off.

Then start the car and read what the voltage is with the voltmeter connected exactly as before.

You should see about 12.5V with the engine off, and something between 13.6 and 14.7(ish) as you rev the engine.

If you see more than 14.7 with the engine running then your Dynator is putting out too much voltage - this will over time ruin your battery, but the 123 should be ok up to about 20. If you see less than 13.5 then the Dynator isn't putting out enough volts to charge the battery.

If you don't have a scope what you can try is to put your voltmeter on the AC scale - if it reads more than a couple of Volts, then that indicates that one of the diodes in the diodes in the Dynator is blown.

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

Topic author
rswaffie
Posts: 801
Joined: Sat Jul 19, 2014 7:56 am
Location: Lincolnshire
Great Britain

#19 Re: Trouble shooting 123 dizzy

Post by rswaffie » Fri Jan 11, 2019 6:49 pm

Great, many thanks Jagwaugh.
Richard

S1 3.8 FHC Opalescent Golden Sand with Tan Trim 889504
Nearing completion of a comprehensive nut ‘n’ bolt restoration in my small, but utilitarian garage :wrench: :hammer: :fingerscrossed:

Link:
BBcode:
HTML:
Hide post links
Show post links


Tom W
Posts: 272
Joined: Sat May 05, 2018 10:18 am
Location: UK
Great Britain

#20 Re: Trouble shooting 123 dizzy

Post by Tom W » Fri Jan 11, 2019 8:21 pm

My 123 wasn’t good to 20v. At about 15v, it causes the ignition to cut out, thought it doesn’t seem to have caused any permanent damage. I had a faulty relay in the alternator circuit, this caused the regulator to see a lower voltage than the alternator was putting out, and concequently the car got overcharged.
Tom
1970 S2 FHC

Link:
BBcode:
HTML:
Hide post links
Show post links

Post Reply Previous topicNext topic