Electronic Dizzy

[freeflyd]

Hey guys,

Where can I get one? What should I ask for, and how much do they cost?

Oh, 89 model 4Y

[Mr_B]

Hi Dawie,

Again I speak under correction(by more knowledgable forum species ), but as far as I am aware the OEM one's come of the 3Y engine, available from engine importers. The one that is on my lux is genuine TOY and has 3Y stamped on the housing. I unfortunately have no idea of the cost, but I am also interested to know, for my pending EFI conversion(I want to keep on unmodded dizzi in the kit, just in case).

Bretton

[BenHur]

Just be careful some 3Y ones do not have a advance and retard mechanism and is fixed. It will work great for EFI conversions but not for Dawie's setup with a carb

3y Dizzy which is locked (not advance and retard) but it also does not house the ignitor, instead it has a second pick-up underneath to measure the engine's position (crack angle)



4y Dizzy with build in ignitor and advance and retard mechanism

[Toybox]

Bennie, i dont suppose you would have one of those fixed 3Y dizzy's lying around, or know where i could find one?

[BenHur]

The one I have is spoken for but I am sure we can make a plan. Do you want it as is or modified with Optical pickup ready for an aftermarket ECU?

[Toybox]

As is i think. i'm curious to see how this EMU handles the mag pick-up and can always modify it to optical later.

I'd like to see if i can get the setup to run full sequential...

[Toybox]

okay got one from Boston importers....

[Mr_B]

Hi Jonathan,

According to what I have read on the forum, aftermarket ECU's don't play happily with the Toy magnetic dizzi!!! Or the Hall type pickup! Doing the optical conversion is well worth the trouble, no more elec/magnetic interference and perfect pulse for an ECU!!!

Bretton

[Toybox]

Bretton,

it would indeed seem that way. the thing is i'm not fitting the Dictator EMU. I have opted to go with the Spitronics unit. it seems to handle both the mag pick-up and the ignitor/coil setup differently.

between Bennie and Peet (Spitronics designer) I should be done soon. with any luck the Spitronics EMU will manage the mag pickups. if not i'll change over to optical.

[freeflyd]

I spoke to Toyota and they charge R6 500 for an electronic dizzy.

I found one second hand for R1050 which seems pretty decent. I will only know if it is in perfect working order after my Toy had been put back together. I do have a money back guarantee though. I think the guy has a few more of these if anyone in Pretoria is interested...

[BenHur]

Don't misunderstand me, the Dicktator can work with a Magnetic pickup via a magnetic adapter interface but with the optical pickup it just works so much better. Let me give a basic lesson in Analogue vs. Digital electronics.

Bear with me as the last time I lectured was back in about 1999/2000 so I may be a bit rusted and the theory here also comes from studies which I completed 12-13 years ago so the old gray stuff might be a bit stadig today.

Point no 1: Magnetic pick-up produces a voltage that must be sensed rather than a switching function. The mag pickup is a passive device ( does not require a supply voltage to work) whereas optical and hall pickups are active devices meaning they need a 12/5 Volt supply to the circuit to operate. Thus with an optical or hall pickup a circuit is switched on or off and it does not get influenced by the intensity (voltage) of the pulse, whereas the magnetic circuit is voltage sensitive. It is a simple as stating that a mag adapter is analogue and an optic or hall is digital.



Point no 2: If you look at the sketch you can see what I mean in point no 1 . The top graph is the square wave you will get from an optic or hall pickup and the bottom one from a mag pickup.

As you can see the voltage of the output of the top graph does not influence the trigger time as the ECU just sense the change in state and not the intensity. You can set the Dicktator to switch on both the leading or lagging edge of the pulse.

Now look at the bottom graph. For the purpose of this discussion first understand the horizontal line on the graph does not indicate time per say but rather the count of revolutions that the engine makes.

If the magnetic circuitry that senses the magnetic pick-up is set to sense the change of state, as the engine rotates, at a set voltage of say 6v then the position in the cycle where the "trigger" is sensed (trigger edge) can differ due to a number of reasons which will vary the timing of the system. See the blue vs. red vertical lines and you will see that the position of the trigger edge moves to later in the cycle on as the voltage in the systems drops thus a lower voltage in the system will retard the timing.

The output voltage of the magnetic pickup will vary as the engine speed varies. The trigger edge voltage may also differ as the supply voltage differs. So if your vehicle’s battery goes flatter the supply voltage to the transistor that senses the voltage from the magnetic pickup will differ and the output voltage of the Magnetic pick-up will also differ since it becomes less (lower output voltage) as the engine turns slower. Remember this is a passive device so the magnetic pick-up effectively is a magneto. Remember the dynamos we had on our bicycles, the slower you cycled the fainter the light it made.

What I found on Bulldog was that as the battery became flatter the starter started turning the engine slower up to a point where the engine revolutions were too slow to induce a big enough voltage in the mag pickup for the mag adapter to sense. If I changed the resister values in the mag adapter circuitry to sense the lower voltage at lower RPM so that the ECU would get a proper input from the mag adapter with the flatter battery I could get her to start, but then she was more prone to interference which lead to misfiring under certain driving conditions.

(u)Point no 3:(/u) To continue the discussion of misfiring one must consider that In real life the output will not be a real smooth sine wave but rather a distorted version of it due to harmonics and all sorts of electrical/magnetic interference. If you look at the wiring harnesses of the 3YE engines you will see that those funny Japanese Oukies at Toyota used screened wire in the harness and the ECU was also housed in a metallic container rather than an Aluminium one, to help prevent radio interference in the circuitry. So a distortion of the sine wave may also influence the trigger edge/timing which will cause wrong timing or even misfiring, as I experienced.

(u)Point no 4:(/u) There are also other things that may influence an analogue circuit like a mag pickup for instance internal resistance of the mag coil changing due to heat, and it may again vary the output voltage and so the list goes on.

In modern electronics everything is moving away from analogue (and valves Eric!) to digital since digital is more precise and less sensitive to external interference so why not take advantage of advances in technology?

To conclude today’s lesson in Basic Electronics 101 lets just summarise again:

Magnetic Adapters = Analogue = Old School = Gagga Poefies
Optical Adapters = Digital (square pulse) = The way of the future = Reliable and dependable

*Note the ramblings above is the opinion of the author and that of Hilux4x4, Hilux4x4 will not take responsibility if any of the arguments above is not 100% scientifically correct, nor will Hilux4x4 be accountable for any injuries, death or what ever consequences may occur as a direct or indirect result of anyone implementing some of this advice in today’s lesson with regards to but not only exclusively too changing mag pickups to optical pickups or by someone deciding to digitize his valve radios.

Verskoon maar ek is op verlof dis vrek koud en ek soek enige verskoning om nie uit die bed uit op te staan nie.

[Toybox]

Magnetic Adapters = Analogue = Old School = Gagga Poefies
Optical Adapters = Digital (square pulse) = The way of the future = Reliable and dependable

Bennie, when you put it like that it all makes sense!

[Family_Dog]

Geez Cowboy, did you stumble and fall and then hit your head on a set of Encyclopaedias?


Very well written, Bennie, and mostly true.

Valves rule! Transistors suck!


-Flu_Dog

[Mr_B]

Shoooweee, yes right very rusty indeed.... NOT

Thanks Bennie, in the words of Vernon Koekemoer:

"I are wanting like a optickle pickup asseblief, right man!"

Bretton