> I've got a 1991 Accord that won't start. It ran fine
> daily, sat parked
[quoted text clipped - 11 lines]
> - High side of the coil (post to ground) is open (infinite
> resistence).
> My initial guess is that the coil is bad. That just seems
> so unlikely
> considering it ran just fine when it was parked last week.
> If it died
> while running that diagnosis would be consistent.
>> I've got a 1991 Accord that won't start. It ran fine
>> daily, sat parked
[quoted text clipped - 15 lines]
> respectively, so the resistance checks suggest the coil is
> good.
How does "infinite resistance = 12.8K to 19.2K ohms?
IMO,infinite R = OPEN = bad coil.
Of course,he should be measuring from either one of the LV tabs to the EHT
output terminal(post) for that secondary resistance reading,as the igniter
will not be grounding the coil.

Signature
Jim Yanik
jyanik
at
kua.net
Elle - 30 Nov 2006 15:25 GMT
> "Elle" <honda.lioness@nospam.earthlink.net> wrote
>> "The Reverend Natural Light" <reverend@fourthgen.org>
[quoted text clipped - 10 lines]
> How does "infinite resistance = 12.8K to 19.2K ohms?
> IMO,infinite R = OPEN = bad coil.
I thought his meter might not be able to register high
resistances. Maye this is erroneous on my part...
Jim Yanik - 30 Nov 2006 19:37 GMT
>> "Elle" <honda.lioness@nospam.earthlink.net> wrote
>>> "The Reverend Natural Light" <reverend@fourthgen.org>
[quoted text clipped - 13 lines]
> I thought his meter might not be able to register high
> resistances. Maye this is erroneous on my part...
Most any meter should be able to read 200K ohms full scale,up to 2 megohms
FS is very common.
My $3 Harbor Freight DMM has a 2 Meg range,my 4.5 digit DMM goes up to 20
Meg.My analog Simpson 270-3 goes up to 2 meg FS.

Signature
Jim Yanik
jyanik
at
kua.net
Elle - 30 Nov 2006 21:05 GMT
> "Elle" <honda.lioness@nospam.earthlink.net> wrote
>> I thought his meter might not be able to register high
[quoted text clipped - 7 lines]
> DMM goes up to 20
> Meg.My analog Simpson 270-3 goes up to 2 meg FS.
I was indeed thinking of an old analog meter my dad still
keeps around, dating from I bet the 1950s or possibly
earlier. (He bought me a digital multimeter a few years
ago.) But I haven't used his old analog enough to realize it
most likely goes up to at least the high k-ohm range. On the
third hand, I reckon it's pretty rare for anyone the least
bit handy with cars these days to be using an analog meter
these days with regularity.
Thanks for explaining all, Jim Y.
> Specs are 0.6 to 0.8 ohms and 12,800 to 19,200 ohms,
> respectively, so the resistance checks suggest the coil is
> good.
I measured from the high tension post to ground and it read (according
to my highly accurate Radio Shack auto-ranging digital multimeter) to
be completely open. That's normal? I was guessing something in the
kiliohms range.
> My money's on the problem being the igniter or some other
> ignition part. The igniter costs under $100 from OEM online
> parts sites and is not hard to replace, given your other
> experience.
I agree, but I'm afraid at this point that it could have damaged the
coil as well. For GM cars I always recommend replacement of the
ignition module as a preventative even if it still works.
> How many miles on car? Years and miles on coil and igniter?
> If originals or non-OEM, again, strongly suspect one of
[quoted text clipped - 4 lines]
> check, bottle of Chevron Techron in fuel tank)? Were OEM
> ignition parts used?
It's the girlfriend's car which she bought from a sleazy used car
dealership with 170k miles on the clock. Who knows when or if it has
ever been maintained or tuned up. The inside of the cap looked about
as bad as I've ever seen. Surprisingly it ran very well, but it is a
Honda.
I'd like to use OEM replacement parts but I *must* get the car running
this weekend (she's driving MY new truck to work right now!) so it'll
get whatever Autozone has to offer.
> A good site for these and other candidate problems for your
> situation, including further checks you can do on the coil
> and igniter:
> http://www.tegger.com/hondafaq/faq.html
Thanks for the link. That's a good site. Wish I had a dwell meter to
perform the recommended test. I'm contemplating plugging my
oscilloscope into the low side to look for pulses before condemning any
$100+ ignition parts that I don't fully understand.
I'll post back what ends up fixing it - might help someone else
someday. Thanks for the advice!
-rev
Elle - 30 Nov 2006 17:36 GMT
> Elle wrote:
>>
[quoted text clipped - 10 lines]
> something in the
> kiliohms range.
I misread the manual, for one thing. I think what you are
measuring is the resistance of a circuit with a capacitor in
it. See the top drawing at
http://home.earthlink.net/~honda.lioness/id5.html. Jim Yanik
can chime in
here and see if I have it right now.
What the manual specifies to check is the resistance between
(1) the high tension positive terminal (called terminal "A"
in the manual, and having a black/yellow wire connecting to
it) and (2) the secondary terminal (= the "coil tower" in
some manuals = the part of the coil going to the distributor
cap and plugs, etc.). It is this resistance that is supposed
to be in the kiliohms range.
Towards the bottom of the following site, the procedure is
described, with specs:
http://www.autozone.com/servlet/UiBroker?ForwardPage=/az/cds/en_us/0900823d/80/0
c/f2/cb/0900823d800cf2cb.jsp
> I'd like to use OEM replacement parts but I *must* get the
> car running
> this weekend (she's driving MY new truck to work right
> now!) so it'll
> get whatever Autozone has to offer.
Some fellow posted in the last year or so that for something
like $200 for parts, he slapped a new Autozone distributor
(housing, igniter, coil, the works) into his Honda and it
fixed it right up.
It's not a long term fix, IMO, because the OEM parts are
superior, from my experience (91 Civic, original owner,
myriad distributor problems) and reading here.
Jim Yanik - 30 Nov 2006 19:51 GMT
>> Elle wrote:
>>>
[quoted text clipped - 17 lines]
> can chime in
> here and see if I have it right now.
He said he was measuring to -ground-,which only works if the igniter is
grounding the coil,which it does not do with the car off.
(grounding the ign.coil charges it up,and ungrounding the coil afterwards
generates the spark voltage.That condenser is actually part of the HV
current path!)
Actually,on a 20K or 200K meter range,it does not matter which side of the
primary he measures to the center post(wht/blu or blk/yel to post),as the
primary is so low a resistance,the meter sees it as a short,and only
measures the High Tension(HT) side of the coil.
That's after measuring the low side of the coil so you know it's not open.
I suspect it's rare the low side (primary) of the coil has any problem.
> What the manual specifies to check is the resistance between
> (1) the high tension positive terminal (called terminal "A"
[quoted text clipped - 23 lines]
> superior, from my experience (91 Civic, original owner,
> myriad distributor problems) and reading here.
Good info you've given here,Elle. Thx!

Signature
Jim Yanik
jyanik
at
kua.net
Elle - 30 Nov 2006 21:08 GMT
> Actually,on a 20K or 200K meter range,it does not matter
> which side of the
[quoted text clipped - 3 lines]
> short,and only
> measures the High Tension(HT) side of the coil.
From the schematic, I see your point and agree. Good lesson.
:-)