Date:         Mon, 27 Oct 2014 05:09:06 -0500
Reply-To:     Max Wellhouse <dimwittedmoose@CFU.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Max Wellhouse <dimwittedmoose@CFU.NET>
Subject:      Re: Vacuum gauge readings
In-Reply-To:  <71BC116B-D690-4D7B-BEEF-A01236E9A3AE@sbcglobal.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

On 10/27/2014 3:22 AM, Michael Magnani wrote:
> Hey Scott and Dennis,
> Thanks for the feedback. Since the induction system is so short, I'm curious where would be a better place to tap for vacuum?
> Mike M
>
> Sent from my iPad
>
>> On Oct 27, 2014, at 0:28, "SDF ( aka ;jim lahey' - Scott )" <scottdaniel@TURBOVANS.COM> wrote:
>>
>> two thoughts ..
>> I'm not sure that's the best place to access engine vacuum for your gauge ..
>> also ..
>> I have never not found 2.1 exhaust valves to not be slightly burnt when
>> taking the heads off for head gasket etc.
>>
>>
>>> On 10/26/2014 1:58 PM, Michael Magnani wrote:
>>> Hi all,
>>> I just completed an installation of a voltmeter, oil pressure, oil temperature and a vacuum gauge in my stock, 1990, 2.1 WBX with 105,000 miles. No leaks, no smoke. Everything nice and as it should be - except for the vacuum gauge. At idle, instead of reading the expected 20 In. Hg, it reads about 13. When I rev it up and then let go of the throttle, the needle will get to 20, but then go down into the 13-15 In. Hg. range.  I've got the 1/8" vacuum tube Teed into the hose between the Air Plenum and the Fuel Pressure Regulator. I've tried two different vacuum gauges to verify that the dashboard gauge is reading properly.
>>> I've verified the ignition timing at 35 degrees BTDC @ 3000 RPM with the temp sensors connected. The engine runs perfectly and makes as much power as it ever did. I'm confused. Can anyone offer any help?
>>> Thanks,
>>> Mike M
>>>
>>> Sent from my iPad
Micheal:  My VDO vacuum gauge reads in that 13-15" range at warm idle
and I rarely see 20" on deacelleration.  I find that the gauge helps me
keep my foot off the floor when driving on the highway, especially when
havingthe throttle only 3/4 of the way down shows 5-10"  on the gauge
and foot to the floor shows like 0" and I seem to travel the same speed
regardless of foot position.....lol

Something a list member advised me many years ago concerning the tubing
for the long run fro mengine to dash was I was using 1/8" soft copper
tubing  and the list member recommended going smaller, so I bought some
plastic 1/16" hose(kinda like the old plastic air shock lines) and
fished it inside of othe copper tubing already in the van's
undercarriage.  The listmember's thinking was that the diameter of the
1/8 ine was stealiing a great deal of vacuum from the engine that cold
be used for operating the power brake servo. The second benefit was that
the gauge had a much faster response time with the smaller hose. YMMV

DM&FS