Date: Thu, 12 Jul 2001 17:48:13 +1000
Reply-To: kelian <kelian@IPRIMUS.COM.AU>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: kelian <kelian@IPRIMUS.COM.AU>
Subject: Re: Hot Weather Effects... and some information.
Content-Type: text/plain; charset=us-ascii
john -
I had similar problems with my '90 caravelle. I had to spend some long days
driving on very hot days, over 40C, up to 45. The pump got noisier during the
day, and after 6 hours or so, would refuse to idle, buck, and hesitate.
Identical behaviour to older cars with fuel vaporising before the carburetor.
Both the pump and fuel lines would be too hot to touch at this point. A new
(expensive) pump improved things a lot, but on extreme heat days, it still
hesitates after idling. A half hour rest to cool down (good for the driver too!)
puts things back to normal.
BTW, bush fire trucks down here are all diesel to avoid this problem.
Ian
John Klun wrote:
> Fellow Listees-
>
> Out here in Delta, CO, in the 'adobe desert', the daytime temperatures can
> hit 105+ in direct sun, every day in the summer. We are in the middle of
> this 3 month period. Our Vanagon and Jetta are parked in direct sun.
>
> I was driving the Van around our field irrigating when I heard the fuel pump
> start to buzz. It buzzed loudly for the remaining time I was out in the
> field. I finished and parked it in its usual spot. A few hours later, when
> the temp dropped down to around 95, I started the Van and no buzz.
>
> Our '86 Jetta GL is somewhat the same. The fuel pump buzzes in extreme
> heat.
>
> The other day, the Jetta wouldn't start. It turned over but not catch. I
> left it alone for a day. I went back out to start it and it caught right
> away.
>
> I checked with Bob Birkholz, my mechanic, and he said that with today's
> gasoline formulations, combined with hot weather and fuel pump pressures,
> the cars suffer from 'vapor lock'. He's also found that when he rebuilds
> old Beetle engines he needs to install a fuel pump in the front tank to
> provide the pressure to get it to the engine (plus a regulator to reduce it
> to the correct pressure in the engine).
>
> We've had many fuel pump failures on our Jetta since 1986 and the 'no start'
> mirrored the fuel pump failure. Of course, I panicked!
>
> The point to this is that severely hot temperatures 100's+ dry, 90's+ humid
> will affect the density of gasoline and your fuel pumps. So be careful.
> Every time the fuel pumps failed in our Jetta, the temps were extremely high
> for the locale: 108 in Kansas, 102 in Florida, humid high 90's in New
> Hampshire.
>
> Thaaaaaat's all volks!
>
> '84 Vanagon GL (Baby) 200,000+ miles?
> '86 Jetta GL (300,000+ miles?)
> '65 Chev PU (Big Black) engine burned up (literally)
| 
