Date: Wed, 3 Aug 2016 20:09:26 -0400
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: Bucking/Loss of power on HOT days
In-Reply-To: <9b35f6f6-ceef-3d4d-663a-03a37ea7368f@turbovans.com>
Content-Type: text/plain; charset="UTF-8"
Audi 5000s also had this. The 84 Turbos had them added as a fix. I think all the 87 and later had them. However those cars had the Bosch CISe (mechanical) fuel injection making vapor lock behind the injectors much more of an issue. They also had fuel pressure accumulators to maintain pressure over a longer period of time.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Scott - IMAP
Sent: Wednesday, August 3, 2016 5:20 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Bucking/Loss of power on HOT days
there actually was a an engine compartment fan ..
fitted to some Datsun 280Z sports cars ...
aimed at the fuel rail area.
a factory fix just for this issue. a Bit dorky, but works.
On 8/3/2016 1:43 PM, Neil N wrote:
> On my '81 with Jetta 2.0, a similar thing happened. The fuel pump has
> always been prone to being noisy ( new at time of swap as was tank
> etc.) but would always get louder on hot days especially if climbing a
> steep grade for any amount of time.
>
> On a trip through a desolate area, with my fuel pump screaming away, I
> pulled over, let engine idle. It sputtered and died. It felt like
> vapour lock. It wouldn't start so I pulled the gas cap and heard a
> "whoosh" of air. With cap off, engine started. On a spare gas cap, I
> removed a little material to help allow tank to pull in ambient air.
> Not sure if this helped but no more stalls. I swapped in a used
> charcoal canister after that and of course reinstalled the other gas cap.
> AKAIK, my fuel pump hasn't been that noisy since.
>
> My swap uses the Jetta charcoal canister purge valve which is quickly
> cycled open closed by the ECU. Does the obd1 Suby swap use a similar
> valve?
>
> At one point I wondered if my different purge valve system pulled more
> air, over a given period of time, than the OEM design. i doubt it
> though. Even if it did, the charcoal filter should vent to atmosphere right?
>
> On my swap the fuel hoses likely pick up heat in engine bay but then I
> have to imagine that the WBX fuel hoses being so close to the engine
> case, would also allow fuel to pick up heat.
> OTOH, I can't recall if the WBX return hose is above the WBX engine.
>
> I'd be curious to see how your Suby swap would work with a fuel tank
> having the 12 mm outlet.
>
> Neil.
>
>
> On Wednesday, August 3, 2016, Richard Koerner <rjkinpb@sbcglobal.net> wrote:
>
> Am having bucking and loss of power on very hot days.
>> My van is an 85 2WD (233,000 miles), manual tranny, with a 2.2 Subie
>> engine (recent conversion by California Westys in San Diego), .....
>
>
>> The symptoms are classic "vapor lock"; yes, unusual with pressurized
>> fuel delivery on fuel injected engines, but I've been going through
>> the List Archives and there have been cases resembling vapor lock.
>> Typically, everything runs fine at freeway speeds in hot conditions;
>> the bucking problems start when I pull off freeway and have to
>> contend with stoplights and idling and low speed.
>>
>> This has happened at low elevations but hot (Florida and Laughlin,
>> Nevada) and also at high elevations (Gunnison, Colorado) on a warm summer day.
>> Problem disappears when van is allowed to cool overnight; starts fine
>> and runs fine the next day.....until it gets hot outside and van is moving slow.
>>
>> Mild whining (not screaming) from fuel pump when this happens. I
>> suspect some cavitation and pump damage occurred. Anyway, I've
>> replaced fuel pump....
>
>
>> Other things I've read about include: gas cap, charcoal cannister,
>> bad coil, fuel pressure regulator, bad ignition coil.
>>
>>
> --
> Neil n
>
> Blog: Vanagons, Westfalia, general <http://tubaneil.blogspot.ca>
>
> 1988 Westy Images <https://picasaweb.google.com/musomuso/New1988Westy>
>
> 1981 Westfalia "Jaco" Images, technical
> <http://tubaneil.googlepages.com/>
>
> Vanagon-Bus VAG Gas Engine Swap Group <http://tinyurl.com/khalbay>
| 
