123 ignition for Datsun L6 on my L28 | The Z Club of Great Britain
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123 ignition for Datsun L6 on my L28

Discussion in 'S30 (240Z / 260Z / 280Z)' started by AliK, Apr 11, 2019.

  1. AliK

    Z Club Member
    Staff Member Moderator

    Well z-heads, I was imagining a "wow this is the best money spent no flaws" style write-up but it appears that the 123 Ignition distributor has impressed and disappointed me in equal measure. Am I being harsh? Well, at this price point 123 set the expectation bar rather high.

    Out of the box you get what you see below. Well packaged and at first glance looks well made. The bracket for L28 is a very nicely machined bit of kit.



    The installation instructions need more work and while there is a video online, it's a bit amateur and more importantly lacks the necessary installation shots.

    Here's a link to the instructions http://www.123ignition.nl/files/manuals/123manual_TUNEPLUS.pdf

    And the low budget installation video:

    So to install, I took out the plugs and turned engine to the end of the compression cycle on cyl 1 I.e. TDC (don't forget there are two TDCs). Taking the cap off the original dizzy, the arm was pointing directly at the radiator panel.

    I kept the 280zx base.

    You install the base plate on the new dizzy taking care to ensure it's the right way up for the dizzy base, otherwise it's near impossible to get an Allen key on it. You don't want it tight at this point.

    The rubber o-ring had to be moved out of the notches and put right up against the base plate to accommodate the 280zx base which has a reamed out bit exactly for the O-ring.

    Next up you screw the dizzy on and connect the red and blue power wires but not the black which is the coil negative that gets switched on/off during operation.

    Our dizzys spin anti-clockwise, so you have to turn the distributor body clockwise until the green LED just comes on. It can be seen through the aluminium ring's holes. This is a nice feature as you can orientate the dizzy to where you want it to be. Would have been useful to have in the instructions that the LED goes on and off several times at different points in the rotation, so you don't have to accept the first "on position".

    After that, you can tighten the base plate clip with an Allen key and the dizzy is set up.

    At this point I would recommend noting the position of the rotor against the cap. Also it's worth cranking the engine without the cap on to see the arm moving anti-clockwise.

    While setting up, it became uncommunicative a few times and it had to be reset by joining the red and blue wires.

    Note that unlike the original dizzy, the spring clips holding the cap on, are simply not strong enough to hold the cap down while unplugging the HT leads. In fact, I had to bend both a little on the first install to ensure the cap didn't wobble BEFORE I had started putting HT leads on.

    Beware that on the cap, there is a "1" which I was dumb enough to use as my no.1 HT lead position. Don't bank on it!!!! Before cranking the engine, make sure you see how the rotor aligns with which point on the cap. The marked no.1 position on my install turned out to be no.4. Given the firing order 153624, the timing on cranking was in fact 120 degrees - 10 degrees base retarded.

    First symptom is a condition known as "car no-starty"!

    Imagine this: WOT and cranking - the mix gets compressed but not ignited, then as the exhaust valve opens, it gets a spark, ignites and gets pushed into the exhaust as the piston is coming back up.

    Downside: Goodbye baffles in the "turbo" back box!


    Upside: Hello Sean's lovely straight through muffler.


    Four neighbours rushed out of their houses to make sure I was alright - promptly followed by my cross wife telling me off for making too much noise! In fact 3 weeks later the neighbours down the road were still debating who would have set off a shotgun in our road! ;)

    A bit of trouble shooing later and re-orientation of the leads, she fired up.

    Checked it over with the timing light to be sure and it was dead on.

    Upside: I learned that my rev counter is a little optimistic and has a 10% error rate. I love the fact that I can play with the ignition timing without so much as opening the bonnet. And no timing light!!

    Downside: you become a total geek with HOURS of fun on the dual carriageway, testing, pulling over, adjusting, testing etc.

    Setting the vac curve requires a bit of driving first to identify how much vac is being generated at different parts of the rev range on light throttle / fast idle. The MAP gauge is quite useful for that but tiny on the screen when driving. I dialled back the factory settings to zero, monitored vac at idle (1000 rpm for my 270 degree cam), monitored Vac at motorway cruising range 2000 - 4000 and I didn't bother with anything above. Then I added 12 degrees total vac advance - 280zx dizzy was adding 25 degrees which scares the life out of me!

    The car simply would not run as smoothly as before and felt like it was intermittently missing. So bad in fact that stoping after a run up the dual carriageway it kept stalling below 1200rpm and failing to start again. I finally got it going before the battery got too low.

    Having wasted a tonne of time messing with carbs, putting in new plugs, cleaning all contacts again with no better outcome, I decided to rip it out and put in the trusty old dizzy. That is when I discovered an issue which focussed me on the negative points:

    The electrode on the Beru branded cap that comes with it had "fallen" out. The spare cap had the same issue but worse as the pointy bit was missing off the electrode altogether so I couldn't even put it back in. At least with the first cap I was able to force the electrode back into the spring. A spare cap costing £30 on a £400+ Dizzy should not have this issue, end of!



    Replacing the Beru cap and rotor with a Bosch equivalent made a HUGE difference.

    The oil pump drive shaft mating point is too loose causing slack on the rotor arm. A bit of gasket paper had to be used to take up the slack but why am I having to do this on a £400+ bit of kit?


    Some may contend that the shafts on older cars may be worn. I would contend that an item designed for classic cars should have catered for this with a simple spring loaded insert which I will be making myself. The 40 year old 280zx dizzy on the same oil pump shaft has not got this issue so I suspect they just got their measurements wrong.

    I sent feedback to the app developers about the ability to see the curve without being Bluetooth connected to the dizzy and being able to switch between curves for different fuel types or track v road use or simply experimenting. They appear to have actioned that now and I'm sure I wasn't the first to ask.

    Also it would be massively useful to have some data logging for post drive analysis showing revs, vac, timing, speed.


    I set her up with

    10 degrees 500rpm

    19 degrees 800 rpm (anti- stall)

    17 degrees 1000 RPM

    35 degrees 3200 RPM

    38 degrees 8000 RPM

    Here's what the app screen looks like


    Something else that I thought I may feel on the road but can't tell the difference is adding 4 more degrees on the build up to 8000rpm, one for the RR.

    Here's a table I stole from another Z car site which may be useful for those thinking of replicating their original dizzy curves ...


    The Bluetooth connection on the app can't quite keep up with real-time events so the readings are slightly behind the times but we can forgive that.

    Extra functionality

    The immobiliser is quite interesting. The car starts but as soon as it hits 300-400 rpm it shuts down.

    The rev limiter is the best I've experienced. It cuts off 60% of the spark randomly across cyls and is silky smooth. It does confuse the rev counter something silly though - the needle jumps all over the place.

    There is an engine temp dial but I'm not convinced it's true engine temp or could it be under bonnet temp? With my water temp gauge 2/3rds across it was showing engine temp at 80 degrees. To be checked with my laser temp sensor.

    Interestingly my flamethrower coil takes 2.5-3amps according to the gauges which is double what I was expecting.

    In summary:

    The good: fully programmable curve, lots of functionality to play with such as the immobiliser and rev limiter.

    The bad: at this price point the build quality on cap springs, the cap itself as well as a less than snug fit to the oil pump drive shaft, lets the side down. Installation instructions need more detail for the "average" user or frankly any mechanic not familiar with THIS dizzy.

    I will continue to add to / edit this post with experiences as I get used to it.
    Last edited: Apr 11, 2019
    MaximG, Woody928, toopy and 1 other person like this.
  2. johnymd

    Z Club Member

    Great write-up. Just to add, as you have stated the shaft is loose on the oil pump drive part. If you pull the dizzy out a little you will notice that it only engages by a mm or so and is therefore pretty loose. The best modification IMO is to get the Datsun base plate machined down a few mm so it engages better.
    AliK likes this.
  3. Graeme - CZ

    Graeme - CZ
    Z Club Member

    Great article Alik. For anyone interested Home Built by Jeff, episode 96 shows a similar install on his 240z (or 680 as he calls it) and some of the issues experienced here.

    Sent from my iPhone using Tapatalk
    AliK likes this.
  4. nospark

    nospark Well-Known Forum User

    Thanks Ali
    Yes, others have reported on youtube that the rotor arm does not sit directly under a cap firing node. It can be vaguely between No1 and No4 cap marks. Is this a design fault ?

    Is the bracket that came with the unit thinner than the oem 280zx bracket that you kept on the car ? If thinner then swap or skim down as per Johny's suggestion.

    It is my understanding that when these dizzys first hit the market they had to be adapted by the technically capable purchaser to fit a Datsun. The USA retail distributor (no pun intended) was instrumental in getting the bracket and these other mods (shaft tangs) accepted by the Dutch company so it then became a plug and play unit (in theory).
    I wonder if there needs to be a bit more attention needed re the cap location design and quality as well as the shaft fitment. Perhaps the USA retail distributor could shed some light on these concerns as they were involved with the initial mods.
    Keep your findings coming. There is more mileage in this thread.
    AliK likes this.
  5. moggy240

    moggy240 INSURANCE VALUATIONS OFFICER Staff Member Moderator

    Great write up!!!!!
    AliK likes this.
  6. atomman

    Z Club Member

    Good right up AliK,

    I got one few weeks ago and have been playing around with different curves and stuff, it could do with some data logging in the app , I've been videoing the screen of the tablet to do this ,
    I have also made a vacuum chamber with some advice from a friend with some open cell foam in it to balance out the vac signal , 6 inputs from the weber 151 vac ports with one coming out to the dizzy but haven't tested this yet,

    Will share some curves and photos later when I get home ,

    Ali are you still running SU's ? With the vac signal
  7. AliK

    Z Club Member
    Staff Member Moderator

    Thanks chaps - hope it helps others buy one with more info to hand. When I spoke to the developers, they confirmed lots of requests for data logging too. So let's see if that arrives in some future update.

    Mr nospark - at TDC it would have passed the ignition point so it should point between 1 and 5. I just took the instructions at face value and paid the price.

    The bracket that came with the unit bolts into the 280zx base.

    Johny - that's good advice / observation!! I will defo look into that. I guess once that is done you can't go back to a 280zx dizzy again without a spacer washer.

    Graeme - thanks for sharing, quite interesting.

    Mr Atoman - yes I'm on Z-Therapy SUs in-spite of Franky's cyber bullying attempts to get me into triples! (And even more trouble with my wife!!) I'm a big fan of having Vac advance. If not for all the obvious reasons, I like the benefit of having a cooler / happier engine at idle.
    Jimbo likes this.
  8. atomman

    Z Club Member

    Yeah that's my thought to ,

    I know not many run vac on webers but im trying to work out a simple solution ,the vac signal pulses a lot with the webers so the idea of the chamber with the foam is to sort it out into a smooth signal , hopefully , seen it in a 911 flat 6 and it works so fingers crossed ,
    I'm sure some of the old japanesse manifolds a had a vac balance hamber type thing on them like the FET manifold ?


    Edit- looks like that's just for the servo take off
    AliK likes this.
  9. johnymd

    Z Club Member

    Just to clarify which part I would advice you to machine. It is the top of the 280zx base that I would remove a couple of mm from.
    AliK likes this.
  10. johnymd

    Z Club Member

    On the silver car I combine the signals from all the manifold runners then connect a fuel filter that is blanked off, teed into the pipe to a map sensor. This provides enough volume to act as a damper for the pulses. Hope that makes a bit of sense.
    AliK and atomman like this.
  11. AliK

    Z Club Member
    Staff Member Moderator

  12. AliK

    Z Club Member
    Staff Member Moderator

    Update: this I feel is very poorly explained in the instructions so let's be super clear before anyone kills their engine. It may seem obvious, but trust me it isn't when you are dealing with the install / app.

    The instructions say bring your engine to the "static timing point" of your old dizzy. Let's say your stock dizzy was setup at 10 deg BTDC and you followed the instructions. Then you take it out and drop in your 123 dizzy. You have just set your 123 to give 10 BTDC at zero (to 500) RPM. Now you set your curve on the 123 app to have 33 degrees advance at 3000 rpm. What you actually end up with is a total timing advance of 43 degrees!!! But the app will show 33.


    My install was at 0 BTDC such that what is shown on the app is what is actually being delivered. The downside is 123 doesn't give any mech advance below 500rpm so the car needs more cranking for cold starting, but I see this as a VERY small price to pay for eliminating absent minded mistakes when playing with the advance curve.
  13. nospark

    nospark Well-Known Forum User

    Thanks for again giving us the heads up on this cap issue. I,ve just bought a 123 ignition (USB) and agree its a crappy looking cap and rotor. It makes sense to get a Bosch cap and carry the Beru in the car as a spare. It's an expensive dizzy and to pay out extra for a peace of mind lets the product down. (It's not the same league as having a Porsche with the IMS bearing issue hanging over you, but still)

    Also my understanding is that in general dizzys serving over 4 cylinders tend to have a greater diameter so that the terminals can be spaced further around the radius of the cap. When you consider that we will run around 35 degrees mechanical plus say 10 degrees vacuum, that's 45 degrees of variation bandwidth to get the rotor firing efficiently over its allotted terminal - in a small 6 terminal cap. (Out of interest, what degree of advance does the rotor sit exactly over the terminal on this 123dizzy?) I wonder if the 123 dizzy was originally directed at 4 cylinder cars and they havn't bothered to upgrade it's size for 6 cylinder + cars.
    Perhaps I am overthinking this and its not really a big deal.
  14. toopy

    Z Club Member

    Out of interest, how fast does the starter operate normally, could it be getting a bit long in the tooth? reason being, having just replaced mine with a new/recon jobbie from Rockauto, the engine spins way, way quicker than it ever has before!
  15. AliK

    Z Club Member
    Staff Member Moderator

    The USB version is a good shout - especially as with a bit of geekiness you can extract the data and log it. If not offered out of the box that is!

    I wouldn't say the Bosch cap is a huge leap in quality but it is better. Also they have added another cap as an option in the updated instructions PDF.

    I take your point on the cap size but I don't think it's that much smaller than my points dizzy's cap and so far no issues despite my hooligan antics and the recent rolling road abuse.

    Using the timing light I find the spark stability is better / rock solid at higher RPMs than the 280zx dizzy's.

    All said and done I'm getting to really like it at the moment given what I'm doing with it (all to be revealed on my from smoker thread soon).
  16. AliK

    Z Club Member
    Staff Member Moderator

    I had the same experience with the new RockAuto one I used when I replaced the engine.

    It spins at around 200 rpm I think but I have not measured it. What I do know is on the same day, at the same engine temp, swapping between dizzys I have a slightly longer cranking experience with 123 given I have 0 initial timing on one (until 500 rpm) and about 10-12 on the other from zero rpm.
    toopy likes this.
  17. AliK

    Z Club Member
    Staff Member Moderator

    So gang, been a while and I haven’t seen the car in a few months until this week, so time for a quick update.

    On my last event of the year to Goodwood in August, the car was fine one minute, then after adjusting the valve lash it was only firing on 5.5 cyls. She would intermittently miss and all plugs looked pretty much the same colour. A bit fed up and too busy to deal with it, I shut the garage door and left it there all winter.

    Given that my Magnacore cables failed before this issue, I bought some accuspark pre-made ones which I managed to damage one of - and never liked the look of them. So I set about making some that go around the cam cover:


    Now I know I trust the HT leads. The coil is practically new.

    I then set about cleaning up the spark plugs using throttle body cleaner, a wire brush and some wet & dry. Then ensured all are gapped at 1.2mm.

    Problem still existed.

    Next up I cranked the engine with the ht leads off the plugs to see what would happen. Lo and behold, the cap started arcing onto the retaining clip!!!

    The cap is a Bosche one and fitted brand new, never to be moved! So it’s disappointing for it to fail in under 500 miles.

    There are no obvious cracks anywhere or signs of damage inside or out.

    I then wrapped it in half a roll of electric tape and covered the retaining clip. Problem 95% gone away.

    I think 123 Ignition have some naval gazing to do about finding a decent cap. Given they are over £40 delivered they shouldn’t be failing so easily. In fact the Beru caps that failed previously look identical in quality to the Bosch one so I strongly suspect the same factory is bashing them out to the same low quality.

    Here’s a video of the arcing - forgive my babbling please as I was a little high on the petrol fumes during trouble shooting while not firing correctly ;)

    hallie, Huw and tyroguru like this.
  18. Rob Gaskin

    Rob Gaskin Treasurer Staff Member Moderator

    Interesting. Was that discovered after I mentioned my 'shock' when adjusting my carbs?

    Always good to look at an engine when running it in the dark! I had a VW VR6 that had a faulty coil pack and it was so evident when dark.

    It wouldn't be as bad I guess with the plugs connected.

    You sound very post Ali - unlike me with my Stoke-on-Trent accent!
    AliK likes this.
  19. AliK

    Z Club Member
    Staff Member Moderator

    Well Rob I did think of our conversation when I found the plasma ball under the bonnet.

    What made me go there was that with the engine running and pulling individual leads I could hear clicking from that part of the engine compartment. I totally was looking at the coil but then saw the sparks and thought I should have blooming well listened to Rob ;)

    Previously with another issue and coil I could see it sparking off the coil at night (Magnacore lead had failed) and given I had previously shocked myself off the coil it seemed like an obvious candidate / I was convinced it was a coil issue. Never did I imagine something as highly priced as 123 would be sparking onto it’s own clips!!! But I guess it’s a premium product “in development” and using poorly manufactured parts.

    As for sounding posh, that’s just my phone voice. Besides, I was trying to tone it down :p
  20. jonbills

    ZClub Administrator
    Staff Member Moderator

    Only one thing for it, get a Speeduino :)
    atomman and AliK like this.

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