[Shotimes] More on my issue

[Steve Weinrich]

Yes, a coil fault can cause a tach that reads 1/3 low.

The TACH signal (IDM) is a summation of hte three coil drive signals.  If
there is a fault such that the circuit for one of the coils was open or if
the output driver in the DIS was defective, you would get this symptom.

You can check for an open coil/connection by unplugging the DIS connector
that feeds the coil anf look for Vbatt (Ignition ON) at each of the three
wires.  This will detect a gross open.

Steve
----- Original Message -----
From: <james@dhlake.com>
To: <shotimes@autox.team.net>
Sent: Tuesday, July 01, 2003 12:46 PM
Subject: [Shotimes] More on my issue


> I think my problem has been ignition related all along.
> I forgot a symptom to add.
>
> symptoms:
> 217 code in persistant
> tach reads approx 1/3 low
> cylinders 2 and 6 come up in dropout test
>
> All my O2 sensor issues seem to be caused by the ignition
> dropout.
>
> Is there anyway to test the DIS module?
>
> Now that the problem is back I will re-check the coil
> primary side, but could a coil issue cause the tach to drop?
>
> Another possible interesting fact, one spark plug blew out
> of the engine and I limped home on 4 cyl about 1 month before the
> problem started.  The Ceramic blew out of the metal part, it was odd.
>
> James
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