Date:         Mon, 23 Jun 2008 17:53:04 -0400
Reply-To:     Greg Potts <greg@POTTSFAMILY.CA>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Greg Potts <greg@POTTSFAMILY.CA>
Subject:      Re: Engine (VanaJetta) won't shut off when hot.
Comments: To: neil N <musomuso@GMAIL.COM>
In-Reply-To:  <c4e7c5f90806231123g9e9abe8o5824fcc02581e962@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Hi Neil,

Is it running on because the ignition is still on, or is it "run-on"
caused by pre-ignition AKA dieseling???

It's quite possible for a hot engine to continue to run without spark.
Usually that's a sign of WAY too much heat in the combustion chamber,
whch could be caused by a lean-running FI/Carb, bad timing, the wrong
spark-plug or some other malfunction.

Most of the Bosch FI systems I know of should have provisions to prevent
dieseling but I am not sure if yours is one of them, so I thought I'd
throw this out there.

Happy Trails,

Greg Potts
1973/74/79 Westfakia "Bob the Tomato"
1987 Wolfsburg Weekender Hardtop
www.busesofthecorn.com
www.pottsfamily.ca


neil N wrote:
> Hi all.
>
> Just took my VanaJetta for a real test run. Runs much better now!
>
> Ignition switch is fairly new, worked fine before conversion, and if
> "new" engine cold-warmish, works fine.
>
> When engine hotter after short hwy. run, it won't shut off.
>
> I put in a separate relay to supply power to Jetta ignition coil.
>
> I suspect heat as the culprit.
>
> If a relay gets too warm-hot, would this cause it to stay "on"?
>
> Here's a pic of relay box/exhaust:
>
> http://tubaneil.googlepages.com/exhaust.jpg/exhaust-full;init:.jpg
>
> Maybe relay box is too close to exhaust or exhaust too exposed.
>
> Would a heat shield on exhaust or relay box help that much?
>
>