'93 civic, engine cuts out while driving on highway ?

Oooh, bad. Aftermarket cap?

Like jim says, it's possible. Apparently the igniter controls its own
dwell by sensing back EMF as the coil charges up. I guess if the coil
ends up oversaturated, the excessive backwash HT voltage thus generated
may serve to damage the igniter.

That's very possible. The entire system exists for the sole purpose of
making a spark jump at the plugs. If anything at all interferes with
that goal, the rest of the system will be subject to abnormal load,
possibly to the point of inducing failure.

By the way, I know OEM parts are expensive, but I strongly advise you to
replace your igntion components with OEM only. Anything else is asking
for trouble.

 

Oooh, bad. Aftermarket cap?

Like jim says, it's possible. Apparently the igniter controls its own
dwell by sensing back EMF as the coil charges up. I guess if the coil
ends up oversaturated, the excessive backwash HT voltage thus generated
may serve to damage the igniter.

That's very possible. The entire system exists for the sole purpose of
making a spark jump at the plugs. If anything at all interferes with
that goal, the rest of the system will be subject to abnormal load,
possibly to the point of inducing failure.

By the way, I know OEM parts are expensive, but I strongly advise you to
replace your igntion components with OEM only. Anything else is asking
for trouble.

 

Oooh, bad. Aftermarket cap?

Like jim says, it's possible. Apparently the igniter controls its own
dwell by sensing back EMF as the coil charges up. I guess if the coil
ends up oversaturated, the excessive backwash HT voltage thus generated
may serve to damage the igniter.

That's very possible. The entire system exists for the sole purpose of
making a spark jump at the plugs. If anything at all interferes with
that goal, the rest of the system will be subject to abnormal load,
possibly to the point of inducing failure.

By the way, I know OEM parts are expensive, but I strongly advise you to
replace your igntion components with OEM only. Anything else is asking
for trouble.

 

From the pictures of an igniter you posted awhile back,the igniter has a
control IC that measures the emitter current while the coil is charging
up.I believe there's a resistor printed on the ceramic substrate that is
the current sensing resistor.

There should be a catch or snubber diode to prevent back EMF from damaging
the igniter,it may be integral with the switching transistor;they do the
same for TV flyback HV supplies.(they also use current sensing to control
coil current,lots of switching power supplies also use it.)

 

An exception would be the most expensive part, the igniter. You should be
able to retrieve a decent used OEM igniter from a local wreckers for about
five or ten bucks.

 

An exception would be the most expensive part, the igniter. You should be
able to retrieve a decent used OEM igniter from a local wreckers for about
five or ten bucks.

 

An exception would be the most expensive part, the igniter. You should be
able to retrieve a decent used OEM igniter from a local wreckers for about
five or ten bucks.

 

"Emitter current"... What's the difference between that and "back EMF"?

I remember this being mentioned way back while we were discussing the
igniter pages before I made those pages up. Thanks for the reminder.

So then maybe the OP's igniter simply suffered a random failure.

I've got 295,300 miles and seventeen years on my original igniter.
Borrowed time?

 

"Emitter current"... What's the difference between that and "back EMF"?

I remember this being mentioned way back while we were discussing the
igniter pages before I made those pages up. Thanks for the reminder.

So then maybe the OP's igniter simply suffered a random failure.

I've got 295,300 miles and seventeen years on my original igniter.
Borrowed time?

 

"Emitter current"... What's the difference between that and "back EMF"?

I remember this being mentioned way back while we were discussing the
igniter pages before I made those pages up. Thanks for the reminder.

So then maybe the OP's igniter simply suffered a random failure.

I've got 295,300 miles and seventeen years on my original igniter.
Borrowed time?

 

"back EMF" is the current generated when the coil is -disconnected- from
the charging current,or as commonly called,the "flyback current". The IC
measures the CHARGING current,thru a resistor from emitter to ground(while
the transistor is ON).
The "back EMF" is the high voltage discharge generated for the spark
plugs when the coil's magnetic field collapses when the charge current is
switched off.Part of it's path is thru the snub diode/condenser,around the
switching transistor,to ground.

What is called "dwell" is the time the coil is being charged,when the
points or transistor is "ON" and 12V is charging the coil.The longer the
dwell,the greater the magnetic field built up,and the higher the back EMF
generated when the charge current is disconnected(points open or transistor
switches OFF).

I see no reason for an igniter to fail simply from age or mileage.
I suspect poor heatsinking(that white compound between the ceramic
substrate and the aluminum of the distributor) or coil/wire arcing
transients.Grime buildup can also interfere with heat transfer or allow for
leakage currents to flow across the circuit improperly.Moisture would not
be good,either.

 

OK....

Then it seems like I need to change my reference to "back EMF" to read
"emitter current" on the relevant igniter page.

You have not yet defined "emitter current". Can you?

 

Old wires or old spark plugs, or non-OEM of same, seem to me
to candidates for contributing to failure of the igniter
too. I base this on my experience with my 91 Civic's igniter
(in the years when I was likely using non-OEM wires and/or
plugs, or just not caring carefully for the OEM ones) vs.
Tegger's set routine of replacing rotor, cap, and wires
every five years.

 

The "emitter" is one element of the switching transistor.
(on a schematic representation,the transistor element with an arrow
designates the emitter.direction of the arrow designates whether the
transistor is a NPN or PNP type transistor)

You have the base-emitter(B-E) current[from the IC] that controls the much
larger collector-emitter(C-E) current[coil charging current]. The control
IC measures the total emitter current,decides when to switch the transistor
off when it reaches specified levels,determined by the value of the emitter
resistor.

 

That's what I meant by "coil/wire arcing transients";plug wires breaking
down or a coil insulation breakdown.
I don't think old spark plugs would cause an igniter to fail,unless they
had a cracked insulator or carbon tracks on the insulator from outside
contamination like dirt/grease.

 

Tegger,
i took my igniter apart to see what was inside. (it is labeled
OKI.)

i popped the plastic panel off the back there was sticky (but
not strong) transparent gel around the electronics. I could see
smallish silver wires welded to each outer ternminal and then
connected to contact points/pads on the circuit board.. while
removing the gel *carefully* with Q-tip, one of the silver wires
easily came away from it's pad/tower. then one of the
pads/towers (that the wires connected to) just lifted off the
circuit board ( no force ) this was not good as i could not
budge any of the remaining contact pads by jamming with a Q-tip.
when i inspected the pad and circuit board with a magnifyng glass
there appeaared to be corrosion or oxidation where the loose pads
were mounted

so i tested switching electronics by using sharp probes and
making the test contacts directly onto circuit board pads or pad
mount points... to my surprise the ignitor ****works and
switches ****

So in my case it seems to be a mechanical failure with the
circuit connections... inside the ignitor

rob

 

Tegger,
i took my igniter apart to see what was inside. (it is labeled
OKI.)

i popped the plastic panel off the back there was sticky (but
not strong) transparent gel around the electronics. I could see
smallish silver wires welded to each outer ternminal and then
connected to contact points/pads on the circuit board.. while
removing the gel *carefully* with Q-tip, one of the silver wires
easily came away from it's pad/tower. then one of the
pads/towers (that the wires connected to) just lifted off the
circuit board ( no force ) this was not good as i could not
budge any of the remaining contact pads by jamming with a Q-tip.
when i inspected the pad and circuit board with a magnifyng glass
there appeaared to be corrosion or oxidation where the loose pads
were mounted

so i tested switching electronics by using sharp probes and
making the test contacts directly onto circuit board pads or pad
mount points... to my surprise the ignitor ****works and
switches ****

So in my case it seems to be a mechanical failure with the
circuit connections... inside the ignitor

rob

 

Tegger,
i took my igniter apart to see what was inside. (it is labeled
OKI.)

i popped the plastic panel off the back there was sticky (but
not strong) transparent gel around the electronics. I could see
smallish silver wires welded to each outer ternminal and then
connected to contact points/pads on the circuit board.. while
removing the gel *carefully* with Q-tip, one of the silver wires
easily came away from it's pad/tower. then one of the
pads/towers (that the wires connected to) just lifted off the
circuit board ( no force ) this was not good as i could not
budge any of the remaining contact pads by jamming with a Q-tip.
when i inspected the pad and circuit board with a magnifyng glass
there appeaared to be corrosion or oxidation where the loose pads
were mounted

so i tested switching electronics by using sharp probes and
making the test contacts directly onto circuit board pads or pad
mount points... to my surprise the ignitor ****works and
switches ****

So in my case it seems to be a mechanical failure with the
circuit connections... inside the ignitor

rob

 

Tegger has/had a picture of an igniter on his website,and that one had a
ceramic substrate for a circuit board.It has the resistors printed directly
on the ceramic,"thick-film" resistors.It makes a very durable,reliable
component.

Was yours an epoxy-glass (or worse,phenolic) PCB with soldered-on
(discrete)resistors?
If so,I wonder if it were a non-OEM igniter?
Maybe you could post a pix or 2 somewhere?

 

Still do, as a link to Grahame Wood's page in the UK:
http://www.gcw.org.uk/rover/igniter.htm.

Send 'em to me. I'll put them up.