Lotus Elan and Lotus Elan Plus 2 Forums

The accuspark ignition system works (so I'm told) by utilising the "halls effect". That is a magnet passes through a magnetic field generated by a coil and creating a voltage. Correct?

So does the voltage generation happen when the magnet enters or leaves the field?

The reason being that it is easy to find the position of the magnets (see image).

If I make the assumption that the coil is in the middle of the "signal module", by turning the distributor so that the magnet corresponds to the middle should give an approximate firing point?

Is this nonsense?

Vince

I think that would be a good enough starting point then fine tune with a strobe?

John

Follow the instructions provided, point the rotor arm at No 1 pickup in the distributor, start engine and adjust with a strobe.
The timing of the spark is NOT directly relative to the triggering of the Hall effect sensor, these units have a fixed dwell time at any speed.
FWIW

I have no instructions. The car came equipped with the ignition.

I had to take the distributor out during the rebuild having taken careful note of it's position.



It ran very well but the leads were sticking up at about 1:30. (180 out)

I pulled the distributor out and spun it 180 and now it refuses to run! Strobing (at starter speed - plugs out) shows 10 After TDC. Well retarded. But, with plugs in, engine backfires spectacularly - indicating advance!

Next step may be to put points back in and at least get it running.

Yes put the points back in, as far as I am aware it?s NOT possible to do static timing with these units especially from an unknown position like yours.

A strobe works at cranking speed (you will find). Remove plugs and see what is going on at bottom pulley timing mark while spun. You don't need to know exactly were its switches providing you are at TDC on No 1 cylinder and No 1 plug outlet on cap is set to rotor arm position when dizzy is dropped in. You can dial it in then while spinning. Easiest way by far and you know you are there when you put plugs in and start it. Can tweak when running.
Set up a temporary switch on starter solenoid then you can crank from under the bonnet with ignition on. Need less help then.

Mike

Link to Accuspark.
http://www.accuspark.co.uk/help.html.
Positive at the coil is the most important part to check.
I bought a Powerspark ignition module for my 43D4.

Les.

miked wrote:A strobe works at cranking speed (you will find). Remove plugs and see what is going on at bottom pulley timing mark while spun. You don't need to know exactly were its switches providing you are at TDC on No 1 cylinder and No 1 plug outlet on cap is set to rotor arm position when dizzy is dropped in. You can dial it in then while spinning. Easiest way by far and you know you are there when you put plugs in and start it. Can tweak when running.
Set up a temporary switch on starter solenoid then you can crank from under the bonnet with ignition on. Need less help then.

Mike

Most timing probes that I've used are triggered by the signal to spark-plug 1, so the flashes are at distributor revs speed.

miked wrote:A strobe works at cranking speed (you will find). Remove plugs and see what is going on at bottom pulley timing mark while spun.
Mike

" Strobing (at starter speed - plugs out) shows 10 After TDC. Well retarded.
Tried that and it showed gave inconsistent results.

miked wrote:Easiest way by far and you know you are there when you put plugs in and start it. Can tweak when running.

Getting it to start is the problem.

miked wrote:Set up a temporary switch on starter solenoid then you can crank from under the bonnet with ignition on. Mike

Got one jumped across the solenoid so I can strobe the marks singlehanded. I must have virtually run it in by now!

Elseezed wrote:I bought a Powerspark ignition module for my 43D4.
Les.

I have one of those as well! Far as I can see they are identical.

billwill wrote:

miked wrote:A strobe works at cranking speed (you will find). Remove plugs and see what is going on at bottom pulley timing mark while spun. You don't need to know exactly were its switches providing you are at TDC on No 1 cylinder and No 1 plug outlet on cap is set to rotor arm position when dizzy is dropped in. You can dial it in then while spinning. Easiest way by far and you know you are there when you put plugs in and start it. Can tweak when running.
Set up a temporary switch on starter solenoid then you can crank from under the bonnet with ignition on. Need less help then.

Mike

Most timing probes that I've used are triggered by the signal to spark-plug 1, so the flashes are at distributor revs speed.

I have not said that this is not the case, if I am understanding your statement. I took it as a given that the strobe sensor is connected to No 1 HT lead.

Sorry Vince, missed the earlier bit about spinning at starter speed. Was not trying to be funny. Looks like you took it the wrong way. I was only trying to help out.

Mike

I think you can static time these as per points. Some electronic ignition you can't but the basic hall effect ones you can.

A simple test lamp between the module gnd and 12v should show you the switching. Then you can get a basic time by rotating dizzy as with points.

There no point setting the timing with points and then swapping the module across as my experience was fitting the module significant changed the timing.

miked wrote:Sorry Vince, missed the earlier bit about spinning at starter speed. Was not trying to be funny. Looks like you took it the wrong way. I was only trying to help out.
Mike

And I appreciate it Mike, I was not having a pop!

miked wrote:

billwill wrote:

miked wrote:A strobe works at cranking speed (you will find). Remove plugs and see what is going on at bottom pulley timing mark while spun. You don't need to know exactly were its switches providing you are at TDC on No 1 cylinder and No 1 plug outlet on cap is set to rotor arm position when dizzy is dropped in. You can dial it in then while spinning. Easiest way by far and you know you are there when you put plugs in and start it. Can tweak when running.
Set up a temporary switch on starter solenoid then you can crank from under the bonnet with ignition on. Need less help then.

Mike

Most timing probes that I've used are triggered by the signal to spark-plug 1, so the flashes are at distributor revs speed.

I have not said that this is not the case, if I am understanding your statement. I took it as a given that the strobe sensor is connected to No 1 HT lead.

Ah, I see. You meant: the strobe will flash even at slow cranking speeds, whereas I took it at first to mean the strobe will flash at the same rate as the crank turns (which is incorrect).

vincereynard wrote:The accuspark ignition system works (so I'm told) by utilising the "halls effect". That is a magnet passes through a magnetic field generated by a coil and creating a voltage. Correct?

So does the voltage generation happen when the magnet enters or leaves the field?

The reason being that it is easy to find the position of the magnets (see image).

If I make the assumption that the coil is in the middle of the "signal module", by turning the distributor so that the magnet corresponds to the middle should give an approximate firing point?

Is this nonsense?

Ignitionrotor.png

The Hall effect is created by the magnetic field deflecting current flow along a flat sensor . The deflection of the current flow creates a voltage difference across the sides of the sensor which is used to trigger the ignition electronics. The Hall effect sensor itself works at zero RPM but the electronics normally switch off the ignition at close to zero rpm to prevent overheating if the ignition is left on. Thus you need to set the timing at cranking speeds as the system has to have turned on at these speeds for the car to actually start.

The hall effect voltage measured across the sensor is proportional to the strength of the magnetic field it is exposed to, but not affect by the speed of the magnet field changing. As the magnet passes the sensor the hall effect voltage will increase and then decrease. The electronics will covert this analogue voltage signal to a digital on off signal at some specific voltage level and then trigger the ignition based on this digital signal. Exactly when the trigger occurs versus the magnets relationship with the sensor is not important but it is fixed by the design of the system and will be close to when the magnet is closest to the sensor plus or minus maybe 5 to 10 degrees

cheers
Rohan