Gauges, love 'em or hate 'em. You either have too
many or you don't have enough. My 1985 Toyota 4Runner came with the
SR-5 complement of analog gauges including:
While people may debate the accuracy of the factory gauges, I find they
are OK. They don't give you any real numeric data, but serve to
indicate whether things are normal or not. One gauge I used to have in
my old VW Rabbit was a vacuum gauge. I found it quite helpful to get an
idea of how much reserve power I had, a handy thing to know in an
underpowered 4-cyl. vehicle. For example, if you were climbing a grade
on the highway and came up on slower traffic, if the vacuum was down
near 0", chances are you had no extra power left to pass the
slower traffic. One day, I saw an inexpensive vacuum gauge at the auto
parts store and I picked it up, figuring I'd find someplace to put it
Shortly after that, I got an e-mail out of the blue about someone that
was considering making an A-pillar gauge housing for the '80s model
Toyota trucks. I checked into it, turns out I knew the guy working on
this and expressed my interest in the project. A few months passed and
finally the parts were ordered. More time passed and the parts were in.
I picked up the housing and headed home to see how it fit.
First problem I ran into was how to get the stock a-pillar trim plastic
off. If you look closely at the pictures above, you can see the trim is
held in place by three tabs, the upper two are pressed into holes in
the pillar and will pop straight out with gentle prying with a flat
blade screwdriver, but the bottom one (the leftmost tab in the above
right picture) is hooked into the pillar hole and so must be lifted
upwards, not outward like the rest. To complicate matters, my pillar
trim was secured by a sloppy bead of windshield glue on the glass side.
I had to run a razor blade down the glass a half dozen times before the
trim was free. It should come off easily, don't force it.
Now, time for some gauges. I finally settled on the
I chose to use Intellitronix gauges that I ordered from Summit Racing.
It seems that Intellitronix brand disappeared for a while and was
replaced with the Nordskog brand and now both seem to be in use.
However, it seems that they have moved away from the analog format to
The vacuum gauge was mounted on the bottom to and vinyl tubing run to
the air intake plenum for a signal. I found one fitting at the back of
the plenum with 3 ports, one of which was plugged, that I used for the
The air/fuel meter hooks into the stock O2 sensor circuit and has a
buffer amplifier that isolates the gauge from the ECU in reading the O2
sensor voltage. It works fine and causes no problem with the ECU. I
like the setup that way since I can watch the output of the sensor the
ECU uses in order to see if everything is working OK. Some A/F guages
use a separate sensor and while a wide-band sensor would give a better
reading of air/fuel ratios for engine tuning, you would not directly
know if the stock sensor is working properly.
The fuel and air tank pressure gauge uses 100 psi senders. One is
installed in the fuel injector rail (drilling and tapping the end of
the rail to accept the sender) and the other sender was installed in
place of the analog gauge in my on-board air system. The fuel injector
rail was end cap was drilled and tapped for 1/8" NPT pipe thread
and a 1/8" - 1/4" NPT street elbow was threaded into that
hole. It was soldered in place as the end cap is fairly thin material
and I was worried about sealing the fitting against fuel pressure. The
solder works well, have had no problems in over 7 years of use. The
fuel pressure sender uses 1/4" pipe thread fittings and due to the
size/shape, needed to be angled downward at a 90 degree angle to fit.
Unfortunately I did not photograph the sender install before putting
the intake back on and it is not possible to take a picture of the
installed sender now. Since I was converting to ARB air lockers, I had
relocated my air compressor switch to the cab and also wanted some sort
of readout of the air pressure in the tank. I ran both senders to a
2PDT switch which then connected to the gauge. Before, when only used
for airing up, the gauge and switch were under the hood.
The gauge housing is set up for 2" or 2-1/16" gauges (the
more common size).
With the gauges in place, I made a wiring harness of sorts (see picture
above), connecting the power, ground and light connections and signal
inputs. The gauge housing attaches with two sheet metal screws (not
supplied) to the sheet metal of the pillar. Space is fairly tight
behind the housing, keep wire sizes to a minimum.
The (nearly) finished project. In the above photos, you can see the
gauges. The top one is fairly close to the driver, I used it for my
fuel/air pressure readout. Not something you need to look at much at
all. Air/Fuel gauge in the center and the manifold vacuum is at the
bottom, where its easiest to see. Vision is slight obstructed to the
left, but not much more than stock.
I have surprisingly found the Air/Fuel meter to be very handy while
driving, more so than the vacuum gauge. With the EFI system, the
optimal engine operation is had in what is called "closed
loop" mode, that is when the ECU is reading the residual oxygen
level in the exhaust gas and adjusting the fuel injector timing to get
an optimal air/fuel ratio (14.7:1). This mode is easy to detect on the
A/F meter, as the needle "twitches" back and forth between
lean and rich about once a second or so. I have found many occasions
where I might have a choice of gears to run in on the road. Maybe I can
have it floored in 4th gear up a grade or drop to 3rd and let it rev
higher with less throttle. Conventional wisdom would say that 3rd gear
would be the best, but in 4th, it'll stay in closed-loop mode, while in
3rd, it'll go to full rich. I find these sorts of situations arise at
higher elevations with lots of gradual up hills, such as you find in
the basin and range country in the west. When pulling a 10 mile long
grade, if you can do it in closed-loop mode, it is likely saving gas
over doing the same hill at full rich.
The gauge housing is a semi-custom design that fellow wheeler Jeff Moskovitz had fabricated. Cost
was less than $60 including shipping (1999 prices, somewhat higher
now). Feel free to consult the A-pillar FAQ page at: