Probably one of the worst things you can do to your Sy/Ty is
install a boost gauge in either the MAP signal or the fuel pressure
signal. Those two devices are very important to the proper operation
of the ECM and the fuel system. If you install a mechanical boost
gauge in one of those lines, that six feet of hose has to be pressurized
before the MAP sees the true pressure in the system.
You're probably saying, "That makes sense, but where do
I install a boost gauge, now?" There are a couple of places
that will work, but I'm gonna show you how to plumb it into the
vacuum source for the power brake booster.
Please pardon my non-expert photography skills...
As you can imagine, the line you are going to work on is the
one running from the upper intake over to the power brake booster.
First, you need to remove that hose from the brass fitting that
is screwed into the upper intake. If you have the stock setup,
all you have to do is squeeze that hose clamp with a pair of pliers
and wiggle that clamp down the hose. The hose should pull off
that fitting after that.
Next, you need to remove that brass fitting from the upper intake
manifold. Just use a wrench... it's a typical right-hand 3/8 pipe
Here's where folks will differ in their install. The hole in
the upper intake is a 3/8 NPT, and that hose barb is a 1/2...
pretty common stuff... BUT there doesn't seem to be a small, one-piece
fitting that'll give you a port for your boost gauge. Some folks
are using a brass 'T' with a couple other fittings, but I wanted
my setup to be smaller.
I found a fitting at a local hardware store that was 3/8 NPT
male on one end and 3/8 NPT female on the other. That allowed
me to use my original hose barb fitting for that brake booster
hose. The wall was fairly thick, so I just bought a 1/8 NPT tap
and made my own custom fitting.
I coated my hose fitting with pipe dope, and screwed it into
the new fitting I found. I then stuck that in a vise and drilled
and tapped a 1/8 NPT hole in the side. Most boost gauges use either
rubber hose or small plastic tubing for their install, and most
of 'em come with 1/8 NPT fittings.
Typical small hose fitting on 1/8 NPT fitting.
Typical compression assembly on 1/8 NPT fitting.
Next, you need to install that new fitting in the upper intake
(with pipe dope or teflon tape, of course). You'll find it a lot
easier to install if you don't already have the boost fitting
screwed into the custom fitting.
Keep turning that fitting until the hole for the boost fitting
is pointing toward the firwall. Now, put some pipe dope or teflon
tape on the boost gauge fitting and screw it into the custom fitting...
nice and snug. [see, I told you some of these photos weren't too
Now put it all back together and hook up your boost gauge. If
you decide to sell the truck as completely stock, all you have
to do is remove that custom fitting, and your boost gauge.
I found a very similar fitting in my latest Jeg's catalog. Part
number 710-65310 is a 3/8 NPT male / 3/8 NPT female fitting with
a 1/8 NPT hole tapped in the side ($10.99 in catalog 'V' - Sep
'99). The only difference between that fitting and mine is that
the Jeg's (actually Moroso) fitting is longer.
good - you won't have to install your stock hose barb fitting
before you drill for the 1/8 NPT boost fitting... plus the
hole is already there!
possibly bad - it will be more visible, due to its extra
length... only an extra 1/2 inch... give or take
Now comes my sales pitch <grin>. If you want a really short
adapter, but don't want to buy the 1/8 NPT tap, and/or you can't
find that 3/8 male / 3/8 female fitting, I can build one for you.
At first, I thought I would be able to beat the Jeg's price, but
the cost is going to be similar to the Jeg's piece, because I
have to supply a new 3/8 NPT male / 1/2 hose barb fitting. I forgot
that the boost-tap hole is drilled through that hose-barb fitting
|3/8 NPT male / 3/8 NPT female fitting and |
3/8 NPT male / 1/2 hose barb fitting
with 1/8 NPT hole for boost tap
|1/8 NPT male / 1/8 tubing compression fitting||$3.00 |
|1/8 NPT male / 1/8 hose barb fitting||$2.00 |
Prices DO NOT include shipping. So to save more money, you should
order several <grin> US Postal Service Priority Mail is
$3.20 for packages up to two pounds, so you can safely assume
about $3.20 for shipping
Residents of TX please add 7.25% sales tax. Residents of
Garland, TX please add 8.25% sales tax.
Canadian residents please include an extra $3 per kit for the
additional shipping costs. You'll need to send me a check made
out in US funds and drawn on a US bank... or a Postal Money Order
in US funds.
Make your check payable to "Ron Gregory" and mail it
(along with ship-to address and part numbers) to:
2917 Snapdragon Court
Garland, TX 75040-2833
Then, send me some e-mail,
so I'll know the check is coming. That way I'll be looking
for the check. As usual, I will send you e-mail confirmation upon
receipt of your check.
1999 Auto Performance Engineering
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