Hi Michael ..
I wouldn't say the induction system is 'that short' ....from throttle
valve to intake valves is a nice distance.
( longer on the 'equivlant' subaru engine ..the runners curve up and
then down , adding length, leading to two intake valves per cylinder ,
and the injectors are a twin spray pattern ..each part aimed right at
its intake valve - very nice .)

I would check into this on your engine though ..
air leaks in the entire intake system ..
I had one engine that was a little reluctant to rev out well ...
could hear the 'air intake moan sound' just fine, but it acted like the
needed fuel wasn't being added.

I found about 10 tiny vacuum leaks ...where the runners join the plenum ..
also check where runners meet the cylinder heads ..listen with a
listening tube..
any hissing ...that's a leak.
  spray carb cleaner works too . .I think the listening method is a
little better.

numerous tiny vacuum leaks could be a factor.
now that I think about it more ..that T'd into the line from plenum to
Fuel P. regulator ...that should work all right I'd think ..
unless there is a leak on the way to your vac gauge ..
or some kine ( Hawaiian lingo ) thing like that.

On 10/26/2014 10:22 PM, 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