

| Subject: | Bad distributor (was: Re: testing the ignition coil (85 1.9L)) |
| From: | Aerowolf |
| Date: | Sat, 18 Sep 2004 17:22:37 -0500 |
Ah, thankee. I have determined that it wasn't the coil at fault, nor the ignition control unit. Nor the distributor cap, or the idle control unit. The problem? Evidently something got a little out of whack inside the distributor... and the plastic holders for the metal tabs for the hall effect sensor shattered. Yay, $150 for a new distributor. Thanks for the help! -Kyle On Thu, 16 Sep 2004 23:03:16 -0400, Daniel L. Katz <katzd54@yahoo.com> wrote: > kyle: > > an ohm meter can be used to check the primary and seconsdary resistances, > as per bently, and the highest range can be used to check for a low grade > short to ground through the case. > > a voltmeter can be used in place of the test light. > > for most purposes, an inexpensive analog multi-meter is the most useful > for this type of work. the swing of the needle is a big advantage over > digital unless very precise measurments are needed. > > as i mentioned, it is rare for a coil to fail, although it does happen, > and sometimers the failure is intermittent due to thermal expansion. > > dan > > > > > On Thu, 16 Sep 2004 18:17:21 -0500, Aerowolf <aerowolf@GMAIL.COM> wrote: > > >I just re-read this, and I realized... there's a mention of "test coil > >without a meter". > > > >What do you do to test the coil WITH a meter? What meter? Does it > >have to be analog or digital or something else? > > > >-Kyle > > > > > >On Mon, 13 Sep 2004 19:26:51 -0400, Daniel L. Katz <katzd54@yahoo.com> > wrote: > >> kyle: > >> > >> a bad coil is truly rare. > >> > >> first get an old spark plug and break off the side electrode to make a > >> tester. then pull off one spark plug wire at the plug and insert tester, > >> with the center electrode a few mm from a convenient ground (engine or > >> body). have an assistant crank and look for a spark. if no spark, pull > off > >> coil wire at distributor and again crank and look for a spark a few mm > to > >> ground. if no spark, and assuming coil wire is ok, then go on to the > coil. > >> your test light should have a wire with an allegator clip, which you > clip > >> to any clean unpainted ground (body or engine) to complete the circuit. > >> with an assistant cranking, test light should turn on more or less > steady > >> when touching coil (+); if not, no voltage at coil (+), which has > nothing > >> to do with the coil. assuming voltage at coil (+), light should flicker > >> when touching coil (-) while cranking; if no light, coil primary is open > >> (bad coil); if steady light, other ignition parts at fault. while > >> cranking, voltage at coil (-) normally spikes to about -300 V, which > will > >> really bite if you close the circuit with your body. if tests at coil > +/- > >> check out ok, then, since no spark, coil secondary probably shorted (bad > >> coil). > >> > >> it is hard on ignition module to make spark jump more than a few mm, or > >> worse, leave high tension side open, so either re-attach plug and coil > >> wires or ground them once you've tested for a spark. > >> > >> it is possible to have spark voltage on coil wire but no spark at plug > >> because of moisture inside cap. > >> > >> this is pretty brief, but outlines what to do to test coil without a > >> meter. > >> > >> as i said, almost all coil replacements are unnecessary - due to a > >> mistaken diagnosis, or just plain wrong guessing. > >> > >> dan >
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