Date: Thu, 11 Sep 2008 07:46:30 -0400
Reply-To: Ken Wilford <kenwilfy@COMCAST.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Ken Wilford <kenwilfy@COMCAST.NET>
Subject: Re: Vanagon dead at walmart--not the coil after all
In-Reply-To: <4d1b79350809101618p85a260en32a304e762dd438f@mail.gmail.com>
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Jim, I was going to email you about this last night but didn't get a
chance. I have dealt with the no spark situation on Vanagons so many
times over the years. The nice part is that there are only three main
culprits in this scenario. The coil (rare but they do go bad). The
Hall Sensor on the distributor (usually intermittant cutting out), and
the ECU (the usual suspect). The ECU in the 86 to 91 Vanagons has the
ignition module (coil drivers) integrated into it. The earlier Vanagons
(80-85) either had points (AC federal version) or a separate ignition
module (everything else except diesel of course). I think this was a
better design because you had a separate unit that wasn't that expensive
if you needed to replace it ($95) and it is mounted on the firewall in
free air to help with cooling.
When they went to the integrated version (86-91) they also moved the ECU
from a place in a nice cooling air stream to under the rear seat. So
they added components that develop a bunch of heat then they stuck it
somewhere where it will get very little to no air flow (ever look under
your rear seat lately? Betcha stuff is stacked on top of where the ECU
lives.)
The ECU lives in a black metal box off to the right under the rear
seat. Not only did they add heat, and move the unit to a bad spot for
heat but they also did a poor job at the factory of soldiering the
resistors that generate all that heat. So now you have way more heat,
no air flow, and bad soldier joints from the factory. Yeah a recipe for
a dead ECU.
I have rebuilt units on the shelf for $250 plus a $100 core. My
rebuilder does the best job. He knows all the weak spots in these ECUs
and rebuilds them better than factory. Then he tests them in a Vanagon
to be sure there are no duds. The only other company out there that
rebuilds these that I know of is called Fuel Injection Corporation. I
got five of these one time to try them out. Not only are they more
expensive than what I sell them for but also I had a major problem with
duds. Out of five, two were actually good. I had one outright dud that
wouldn't allow the van to start and another two that worked but the tach
read double what it was supposed to.
Of course you can find some good used ones out there and there is
nothing wrong with that option, just the fact that used ones are prone
to the same sudden death syndrome and faulty soldier joints.
The only real way to test the ECU is to replace it with a good used one
and see if the van starts. If it does then it is the ECU, if not then
it is the hall sensor in the distributor. I have never really had much
luck with the test for the hall sensor in the Bentley. If you have a
good used distributor handy you could try swapping that in but swapping
the ECU is so much easier as a first try.
I hope this helps,
Ken Wilford
John 3:16
www.vanagain.com
Jim Felder wrote:
> I just got back from walmart parking lot (oh, joy) where I took the
> loaner coil my local shop let me use for troubleshooting. Before I
> removed the suspect coil, I turned on the key and stuck a test light
> on the positive coil terminal connector to make sure it was getting
> power from the ignition switch. It wasn't the switch. So, I swapped
> out the coil (checking connections) and it wasn't the coil.
>
> So, I guess all that's left is the hall effect sensor. I removed the
> distributor and will take it down to have the sensor tested tomorrow morning.
>
> If it is the sensor, anybody have a used one or a used distributor? I
> just check around and they seem mighty expensive.
>
> Jim
>
>