[T3] cool weather idle hunt

[Mark Fuhriman]

Could be a vacuum leak in the air hoses around the engine and intake air
plenum. with the engine idling in your driveway, point a propane torch
(unlit ;) around the hose connections and see if the engine suddenly wants
to rev up. If so, you've found a vacuum leak.

Mark
'69 Fastback

On Thu, Dec 1, 2016 at 5:02 PM, Daniel Nohejl <d.nohejl at gmail.com> wrote:

>
> > On Oct 27, 2016, at 2:36 AM, Jim Adney <jadney at vwtype3.org> wrote:
>
> > Has anything been changed on your Aux Air Regulator since last
> > winter? It sounds like it may be opening too soon, but, from your
> > description, I get the impression that this isn't really the problem.
> > Could there be another air leak that seals up as some rubber part
> > warms and becomes more flexible?
> >
> > With the engine warm, pull the AAR hose off the air cleaner and close
> > it with your thumb. The idle speed should not change significantly.
> > Is that what you find?
>
> So here’s one from the vault….or at least more than a month ago.
>
> I continue to have a very annoying loping idle that begins about 2 minutes
> after a cold start in the AM. I’ve tried lowering my idle speed to around
> 850 and then to 800 to no avail. I wrote back in October that I’ve pulled
> the AAR hose off the air cleaner and put my thumb over the end and have
> found that the idle dips about 75 rpm. I’ve tried spraying around various
> joints and hoses with carb cleaner and haven’t found anything at all. There
> was no lope during last winter, spring, or summer. It started this fall and
> I haven’t touched any hoses, the intake runner boots, or the intake
> manifolds which I’ve confirmed are tight to the head. Yes, I could just
> accept it, but I’d prefer not to, especially b/c we haven’t had this issue
> before. Any ideas?
>
> And here’s another problem in a similar vein. At the beginning of this
> month, I developed a strange idle problem. The engine would idle normally
> once warm but sometimes would enter a hunt phase with short and sharp peaks
> and valleys. When in traffic, it became problematic b/c if the hunting went
> on long enough, the generator light would come on at the low point.
> Sometimes, the engine would stall if I didn’t get my foot on the gas
> quickly enough after shifting into neutral and getting the parking brake
> on, which is hard to do in NYC traffic while negotiating cabs and crazy
> drivers.  This would go on for maybe 15 or 20 mins in traffic. Then, out of
> nowhere, the idle would suddenly go back to normal. After a few days, this
> issue went away. In the last 2 weeks, it has come back. Tonight, for
> example, in traffic, the car stalled 6 times b/c I couldn’t get on the gas
> quickly enough after getting into neutral. Of course out of nowhere, the
> idle just went back to normal. The other morning, this happened on a bridge
> over the East River. Not fun and potentially dangerous as some overzealous
> driver could easily rear-end me! I’ve tried to replicate the problem by
> pulling on various wires and connectors to no avail.
>
> There are maybe 2 things I’ve encountered that sound like this hunt:
>
> —when we’ve tried a new MPS and had the AFR gauge plugged in and it was
> reading very very lean.
>
> —when the idle speed is around 600 and the motor barely runs
>
> Again, anyone have any ideas?
>
>
>
> _______________________________________________
> VWType3.Org mailing list - type3 at vwtype3.org
> To unsubscribe or change subscription options, visit:
> http://lists.vwtype3.org/listinfo.cgi/type3-vwtype3.org
> If you need more help, contact: gregm at vwtype3.org
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.vwtype3.org/pipermail/type3-vwtype3.org/attachments/20161201/977e5198/attachment.htm>