Date:         Thu, 4 Mar 1999 21:28:58 -0500
Reply-To:     Brigstocke John <brigjfb@SHAW.WAVE.CA>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Brigstocke John <brigjfb@SHAW.WAVE.CA>
Subject:      1986 ignition problem
Content-Type: text/plain; charset="us-ascii"

Hello, I'm a subscriber from some time ago who needs some help.  If you can
direct me where to look if a similar problem has been covered in the
archives - thanks.  If not then many thanks for help in advance.

Our 1986 van with 320kkm has an infrequent problem over the last year,
becoming more frequent lately.  That is it most likely would happen in the
16 km drive to work but may not. The problem is a total failure of the
ignition that oocurs while driving, just as if the igniton key had been
turned off.  The tachometer goes to zero and the engine dies. It may
recover almost instantly without any action or it may recover if the key is
turned off then back on.  Several times after it fails it will restart only
after 30-45 minutes of effort to troubleshoot and try to restart.

What I have done to search out the problem:
1. Checked the power supply and fuel pump relays - they are both ok.  When
failure occurs a reading of the voltage at the ecu shows battery voltage.
2. Checked the spark while cranking with a no-start condition.  There is NO
spark at the coil HV wire.
3. Checked the readings at the ecu connector under the seat: the readings
all appear ok.
4. Checked the output of the Hall sender - it shows a varying voltage but
of low amplitude - what should it really be?
5. If one terminal (the +ve I think) at the coil is removed momentarily and
replaced (with ignition on, engine still not able to start) the fuel pump
cycles on and off. If this is done several times the spark returns and the
engine will start up.  I'm not sure this action actually caused the engine
to be able to start but I didn't do anything else and the spark returned.
6. I checked the voltage supply to the hall sender and it seemed ok.
Couldn't find any bad wires.  Same with the coil wires.

So help!!  We are going on a trip south in 3 weeks and it will be real
stressful to try and make it as runs just now.

About three years ago I had a problem with the air-flow meter which was
fixed with mod suggested on this list - the add a capacitor to the output
to the ecu.  That problem was different in that the tach still continued to
function when the engine cut out.  So I have assumed it is unrelated to the
air-flow meter.  Can't see how that would affect the tach anyway.

Thanks for any help in advance.