Date:         Sun, 17 May 2020 19:30:21 -0700
Reply-To:     David McNeely <davmcneely40@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David McNeely <davmcneely40@GMAIL.COM>
Subject:      Re: Spark Plug Wire Shock
Comments: To: Dennis Haynes <d23haynes57@hotmail.com>
In-Reply-To:  <MN2PR08MB62393250ACD93D4170A257C9A0B80@MN2PR08MB6239.namprd08.prod.outlook.com>
Content-Type: text/plain; charset="UTF-8"

thanks, Dennis.  Haven't actually done that on the Vanagon, but many times
on vehicles with rubber boots, no metal shields.  Sorry if I caused anyone
to do this with the Vanagon when it should not be done.  mcneely

On Sun, May 17, 2020 at 5:53 PM Dennis Haynes <d23haynes57@hotmail.com>
wrote:

> I've known electricians that would use their fingers to test for power.
> Some things even if done successfully are not the best of ideas. For the
> Vanagon the metal shields on the spark plug connectors easily get arced to
> when the plug is pulled. Often the ends shorting to that can is the cause
> of the miss. If doing this method use gloves or insulated tongs and be sure
> not to be in contact with the body to complete the ground path.
>
> Now past the safety part, this isn’t a good practice for other reasons.
> The high voltage produced form that open circuit wants to go somewhere. The
> next point of failure is the ignition coil. Any weakness in the coil
> insulation and that arc will make a new path. Then depending on that new
> path it could bridge over to the primary side of the coil. For the 1.9 the
> separate ignition module is relatively low cost. On the 2.1 oops there goes
> another ECU.
>
> A better way to test for a missing cylinder is to disconnect the injector.
> If a cylinder is suspected to be completely out an infrared temp gun on the
> exhaust will pick it up.
>
> Dennis
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
> Of David McNeely
> Sent: Sunday, May 17, 2020 7:56 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: Spark Plug Wire Shock
>
> Removing a spark plug wire while the engine is running is a very long
> standing practice to determine if a cylinder is miss firing.  If you in
> fact had the plug boot firmly in hand, well insulated, you should not get a
> shock.  Done it many times, taught to do so by a long experienced
> professional, my brother.
>
> mcneely
>
> On Sun, May 17, 2020 at 2:15 PM Gene P <olgreywoof@gmail.com> wrote:
>
> > Wait, you did what?  Do you mean you grabbed a spark plug wire and
> > removed it while the engine was running?  I think that jolt would be
> > normal, more volts than I want in my hand.  You need to have the wires
> > loosened (with engine off) and then have something non-conductive to
> > remove them to test that way.
> >
> > From: Jack R
> > Sent: Sunday, May 17, 2020 1:45 PM
> > To: vanagon@GERRY.VANAGON.COM
> > Subject: Spark Plug Wire Shock
> >
> > So, I tried pulling
> > spark plug wires to see if there was a cylinder missing.  When I
> > pulled the
> > #3 wire, I received a jolt!
> >
>