reliable ignition amplifiers - A question for the old gits.

[kbs]

Hi,

As an old git myself, I have memories of 80’s/90’s cars and bikes that used “ignition amplifiers”.

These were driven from an electronic pickup and were ‘dumb’ (the ignition amplifier provided no advance/retard it was just a switch).

Can anyone guide me to a good reliable type of “dumb ignition amplifier” that can be bought cheaply today? I had hoped to use a double unit such as the Bosch 0227100200 but these are very expensive.

I also need a pair of wasted spark coils to work with these – again looking for a cheap solution that old electricians remember to be reliable.

Please note - its DUMB units I'm looking for and these will be driven from a PIC.

Hoping to spend >£10 each for the amplifiers and >£20 each for the HT coils.

Thanks in advance.

 

[MikeMl]

Hereabouts we have a "Pick and Pull" car junk yard. You go in with your own toolbox, walk through rows of dead cars, when you see something you like, you take it off the junker, and then pay for it on your way out.

Otherwise, if you know specifically the make/model of a car that has the part you are looking for, there are parts houses that sell the new modules...

 

[kbs]

Hi Mike,

Thanks for the reply - we have those scrap yards here too, hours of fun.

What I was after is knowlege from someone who works in the other kind of scrap yard - where parts are shelved.
They will have some 'ignition amplifiers' and 'ignition coils' where the shelves are overflowing because (that specific model of) the parts rarely fail. These parts are generally sold cheaper as there is not much call for them. When I was working in a yard, much was thrown away - why keep 1oo of an item if you can only sell 2 a year?

Its just difficult to get access to the people with the knowlege. There is one local yard here in Bristol "all car parts" good stock and a good manager if you can get him. Unfortunalty, the kids who work on the parts counter cant tell an elbow form that other thing and will do what they can to make the customers life diffucult. I've never understood why little Hitlers are attracted to such jobs but every scrappy seems to have at least one (minimum wage thing I suppose).

I have mailed a couple of the cheaper parts houses to see what they can offer - if I'm happy to use unbranded amps then I can get them for under £10. I'm not happy to use unbranded HT coils though and they are more expensive.

Thanks

Keith

 

[tunedwolf]

Volvo used loads of them throughout the 80's/ 90's, on just about every model too, so you should be able to find plenty of those in the scrap yards from the later models like the 760/960 etc
Other than that, you'll be looking for something along the lines of an old Lumenition opto-aftermarket replacement or perhaps something off a different vehicle. The Renault's used them too in the Fuego and 18 as did Honda on the Prelude and a few other models. As far as coils go, I have used both Lucas replacements and Powerspark without trouble

 

[debe]

This is one fairly common type ive found at the local scrap yard for free. Its a J121 unit, there is also another common one that just looks like a TO3 transistor on a heat sink with a plug on it. When collectin these from a scrap yard remember to recover the plug with some length of wire with it.

 

[rumpfy]

Hi,
i have an old 1991 mitsubishi with a BOSCH ignition control module in it. I think the same unit was used in General Motors vehicles as well. I am in Australia and the cars I refer to were australian built cars. The control module was switched from an inductive pick up coil. but I think there may have been later versions which were switched from optical switches. These units comprised a constant pulse width generator and a high power transistor switch. The back EMF when the spark was generated is about 80 to 90 volts peak.
The control module was used on cars with a distributor and the module was built in to the distributor body.
Good luck with your search and I'm sure you will find your module quite easily.
Sometimes you have to be clever and convert a car makers part number to the actual device number; not impossible tho'.

 

[kbs]

Thanks for all the help guys - I'm off to find volvo/mazda ign amps

 

[Ian Rogers]

The Citroen 2CV used wasted spark systems.... See if you can find one of them down the scrappy!!!

 

[Diver300]

The Fiat Cinquecento (1991 - 1998 version) had two double-ended wasted spark coils, so you might be able to get hold of a set of them.

They were run from an engine management computer, so they might take too much current and get too hot if they are a just run from a dumb controller.

 

[debe]

Heres a couple from Subaru vehicles using wasted spark. The modules are basicly 2 igniter modules in one package firing 2 coils for 4 cylinders. Picked these up for free from local scrap yard. They are normaly mounted on top of the dual coil assy on the center of the engine.

 

[kbs]

Rumpfy – Bosch units would be great but I'm struggling to find a few the same for a good price.


Hi Diver,

The coils could be useful but I'm looking for ignition amps rather than ECUs.


The subaru looks like a neat solution – I'll look up the value of those and see what the coils are like. Debe, your heat shrink gun has the same problem as mine! How does the a hot air device leave such sooty deposits?


I'm wondering now if I should buy a dumb ignitor/coil pack combined?

There are these things in ford escorts etc. All in one, hold low to fire – pull up to charge coil – sounds too good to be true?

 

[atferrari]

What does "waste" mean in this context?
Cars? I only drive them. Sorry.

 

[debe]

Wasted spark means one plug of a pair is fired on the exaust stroke (wasted spark) as the other of the pair is fired at ignition point.

 

[debe]

Heres what it means as a circuit. This is a wasted spark type system, on a 6cyl engine.

 

[kbs]

What does "waste" mean in this context?
Cars? I only drive them. Sorry.

As it shows/says above.
A four cylinder engine wasted spark engine will fire twice per crank rev.
Cylinders 1 and 4 (also 2 and 3) fire at the same time although only one cylinder will be on the compression stroke, the other cylinder will be on the exhaust stroke so the spark does nothing. Therfore known as 'Wasted Spark'. This approach requires less semi conductors to switch (1 per 2 cylinders) so was a way of saving money especially in the early days of such systems.
A less well known system is 'wasted fuel injection' where the injector runs delivering half the required fuel - one cylinder the fuel remains behind the closed inlet valve, the other cylinder sucks the fuel through its open inlet valve. Again this saves money by reducing the number of semi-conductors required.
In this context - semiconductor is normally a transistor.

 

[atferrari]

Thanks. I see why now.

We could say that we save by wasting. Go figure...

 

[Diver300]

As it shows/says above.
A four cylinder engine wasted spark engine will fire twice per crank rev.
Cylinders 1 and 4 (also 2 and 3) fire at the same time although only one cylinder will be on the compression stroke, the other cylinder will be on the exhaust stroke so the spark does nothing.

To clarify, a four-stroke engine like that will fire each spark plug once per crank revolution. Because 1 and 4 fire at the same time, and 2 and 3 fire at the same time, there are a total of two firing events per crank rev, but each spark plug fires once per crank rev and each cylinder fires once every second crank rev.

All the single cylinder four strokes I have worked on fire the spark plug every crank rev, because the magneto is on the crankshaft and that is simpler than finding a way to stop the spark happening every second revolution when it isn't needed.

 

[kbs]

and if thats still unclear....

In a wasted spark engine - every cylinder fires every time its piston approches TDC.

Without a cam position (or cam phase) sensor - four strokes can only use wasted spark. When we finally bin the camshaft and operate valves with solenoids, then we can choose which is the compression stroke and run non-wasted spark with only a crank sensor.

This is something I'm really keen to have a go at - I've got an old 8 (verticle) valve engine and as soon as I can find some solenoids suitable that dont cost a fortune....

 

[waid302]

This is one fairly common type ive found at the local scrap yard for free. Its a J121 unit, there is also another common one that just looks like a TO3 transistor on a heat sink with a plug on it. When collectin these from a scrap yard remember to recover the plug with some length of wire with it.

Hello Debe. I am a new member here from the states. It is very common for owners of Ford and Chrysler to convert to more reliable GM's HEI Ignition Module. I have a J121 Unit already with a coil. I am not an electronics expert.

Would I be able to use the J121 with a Carburetor Engine? What would I need to do?

Thank you

Waid

 

[debe]

Depending on what your distributor has in it, if its points then you you need a circuit that will give pulses to drive a J121 module. The modules need to be driven by short pulses eg a reluctor type distributor, they cant have a voltage on the trigger pin when the engine is stopped. (Theres a Ford module that can be used this way with points driving it.)