[E-Type] Here is a procedure to calibrate your oil pressure gauge

I have only done one gauge and here is the result. I hope this
works for all gauges.

Take the oil pressure sender and gauge out of the car. Disable your
car so it cannot be started. If car is started without sender, oil
will be pumped out through the sender hole and your engine will
seize up due to no lubrication. At a minimum take out the keys,
battery and the distributor rotor.

Make a test jig with a 1/2 inch three outlet pex style elbow and
plumb three 2 inch pieces of pex pipe to it. Crimp all connections
or they will blow apart under 60 psi. In one outlet screw in an air
pressure gauge. In another outlet screw in the oil pressure sender
and secure it with a hose clamp ot it will blow out. In the third
outlet screw in the air supply. I have a photo. How can I attach
it? If anyone wants the jig photo please Email me at
@Dennnis and put Jag oil pressure gauge in the subject line.

Using a 12 volt battery, wire the folowing circuit

wire from one terminal on oil pressure gauge to the sender male
spade connector

wire from the metal base of the sender (ie wrap bare wire around
the base where the thread are) to the -ve of the battery

On the back of the oil pressure gauge pull out the two cork bits
covering the adjuster access holes.

Gradually apply 60 psi to the sender (wearing safety goggles)

Wire +ve battery terminal to the other terminal on the oil pressure
gauge. In this wire you must put a 1 amp fuse. This is a safety
measure against short circuits. If you are not both qualified and
familar with electrical circuits, please find a qualified person to
do all the electrical

The circuit should now be live ie the gauge should read pressure

Wait two minutes for the gauge reading to settle

Looking at the back of the gauge, turn the left side adjuster
whichever way is needed to make the gauge point to 60 psi. The
adjuster slot needs a small screwdriver. The motion is to move the
slot perpendicluar to the slot direction. Moving the slot to the
right makes the gauge needle reading go towards zero, to the left
makes it go towards 60 psi. After you make the adjustment wait two
minutes.

Remove the 60 psi supply from the jig and watch the gauge reading
go towards zero. Wait at least two minutes.

If the gauge reading is not zero, turn the right adjuster until the
reading is zero. Moving the slot to the right makes the gauge go
towards 60 psi, to the left, the other way. Wait at least two
minutes

After you have zeroed it, apply 60 psi and recheck the reading.

To precisely calibrate the gauge and make the readings REPEATABLE
is virtually impossible. Some may wish to tap the gauge to help
readings stabilize. If you get it to properly read zero psi and
then read within 5 lbs at 60 psi count the count as done! Another
problem with old gauges is that they may move very slowly as they
approach zero and or 60 psi. We live with a lot of worse things!
Tell me how it works out for you. Dennis–
Dennnis
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–


Search the archives & forums - http://search.jag-lovers.org/
Subscription changes - http://www.jag-lovers.com/cgi-bin/majordomo
Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

In reply to a message from Dennnis sent Thu 31 Jul 2008:

Dennis-

This is a good procedure, but what about the voltage
stabilizer? My understanding is that this gauge, along with
the Smiths temperature and fuel level gauges, works on 10
VDC, not the 12-14 VDC produced by the battery. The
so-called voltage stabilizer is supposed to provide the 10
VDC needed by these gauges, so it really is a 10 volt
regulator. I suspect this 20-40% voltage differential would
significantly affect calibration. I think the voltage
stabilizer should be added to your circuit and procedure.
Good luck,–
The original message included these comments:

Wire +ve battery terminal to the other terminal on the oil pressure
gauge. In this wire you must put a 1 amp fuse. This is a safety


Kent
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–


Search the archives & forums - http://search.jag-lovers.org/
Subscription changes - http://www.jag-lovers.com/cgi-bin/majordomo
Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

In reply to a message from Kent Holcomb sent Thu 31 Jul 2008:

Kent,
The IVR only powers the fuel and temp gauges, not the OP gauge.–
Ray Livingston - '64 OTS Santa Cruz, CA
Santa Cruz, CA, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–


Search the archives & forums - http://search.jag-lovers.org/
Subscription changes - http://www.jag-lovers.com/cgi-bin/majordomo
Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

In reply to a message from Kent Holcomb sent Thu 31 Jul 2008:

The voltage stabilizer feeds the temp and fuel gauges because the
sensing devices are essentially rheostats – resistance devices.
The oil pressure gauge and sender are both thermoelectric devices –
current flows through heating wires that in turn heat a bimetallic
cantilever beam. In the gauge the tip of the beam is connected to
the pointer. In the sender, the tip of the beam is a set of points
that go to ground.
If there is pressure, the points are closed and current flows,
heating (and bending) both elements. In the gauge the pointer
climbs. In the sender the pressure eases on the points. This
continues until the element in the sender bends enough to open the
points, current stops, and the elements start to cool until contact
is made, and so on.
Because both components are the same, they operate independant of
voltage on the loop. Not so if the sending element is a rheostat,
thus the stabilized voltage. I should point out that the voltage
stabilizer operates on the same principle as the oil pressure
sender and the opening/closing averages to 10 volt. In reality it
is either zero volts or full volts.–
The original message included these comments:

This is a good procedure, but what about the voltage
stabilizer? My understanding is that this gauge, along with
the Smiths temperature and fuel level gauges, works on 10
VDC, not the 12-14 VDC produced by the battery. The
so-called voltage stabilizer is supposed to provide the 10
VDC needed by these gauges, so it really is a 10 volt
regulator. I suspect this 20-40% voltage differential would
significantly affect calibration. I think the voltage
stabilizer should be added to your circuit and procedure.


Pete 70 XKE (193K) 88 XJ6 (244K) 88 XJ6 (234K) 60 Mini
Severna Park, Maryland, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–


Search the archives & forums - http://search.jag-lovers.org/
Subscription changes - http://www.jag-lovers.com/cgi-bin/majordomo
Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

In reply to a message from Jaguarpete sent Fri 1 Aug 2008:

Pete,
I suspect the real reason the OP gauge is not on the IVR is
because it draws 4-5X more current than the other two - more than
the IVR could possibly provide.–
Ray Livingston - '64 OTS Santa Cruz, CA
Santa Cruz, CA, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–


Search the archives & forums - http://search.jag-lovers.org/
Subscription changes - http://www.jag-lovers.com/cgi-bin/majordomo
Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

In reply to a message from Jaguarpete sent Fri 1 Aug 2008:

Nice explanation Pete - with/without Ray’s supplementary. Thanks to
you both. I knew the basics but hadn’t seen them written out like
that.

Pete–
66 2+2, 68 OTS lump, 94 X300 Sovereign, 94 XJR Manual
Cambridge, United Kingdom
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–


Search the archives & forums - http://search.jag-lovers.org/
Subscription changes - http://www.jag-lovers.com/cgi-bin/majordomo
Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

In reply to a message from Ray Livingston sent Thu 31 Jul 2008:

My Bad! I installed a mechanical OP gauge a few years ago
and do not think too much about the old wiring. When I read
this post I was too lazy to check my wiring diagram.
Instead, I looked at the Nisonger web page I had open to
order some gauge glass and gaskets. Their parts and
accessories page states that the Smiths OP gauge requires
the voltage stabilizer! You would think that they, if
anyone, would know better. Good luck,–
The original message included these comments:

The IVR only powers the fuel and temp gauges, not the OP gauge.


Kent
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–


Search the archives & forums - http://search.jag-lovers.org/
Subscription changes - http://www.jag-lovers.com/cgi-bin/majordomo
Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

In reply to a message from Kent Holcomb sent Fri 1 Aug 2008:

It does say that all 3, oil pressure, water temp and fuel
gauges should be wired from a VR. Howevreen)er, My electric
OP gauge is wired per the wiring chart for Pre-ser. II and
has the 12v (green) lead wired from the 12v lead going
into the voltage regulator. The other 2 (green/ black)
wires on the other side of the VR run over to the water and
fuel gauges. So, maybe there is some misunderstanding as it
seems one can tap into the 12v going into the VR.–
The original message included these comments:

Instead, I looked at the Nisonger web page I had open to
order some gauge glass and gaskets. Their parts and
accessories page states that the Smiths OP gauge requires
the voltage stabilizer! You would think that they, if
anyone, would know better. Good luck,


Mr. Nice Spokes
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–


Search the archives & forums - http://search.jag-lovers.org/
Subscription changes - http://www.jag-lovers.com/cgi-bin/majordomo
Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

In reply to a message from Nice Spokes sent Mon 4 Aug 2008:

I agree. My car and its respective wiring diagram are the
same, i.e. OP gauge power from input side of voltage
stabilizer/regulator. This feed is the same as directly
from the battery, except it is through the ignition switch
and fuse #7. This feed also goes to the voltage gauge on
Series 1.5 and 2 cars, so it clearly should be full battery
voltage. If I had checked the wiring diagram instead of
Nisonger’s web page I would not have posted my question. It
seems your procedure is very good, ‘‘as is.’’ Nonetheless, I
think I will stick with my Smiths mechanical OP gauge
(without any adjustment required). Good luck,–
The original message included these comments:

fuel gauges. So, maybe there is some misunderstanding as it
seems one can tap into the 12v going into the VR.


Kent
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–


Search the archives & forums - http://search.jag-lovers.org/
Subscription changes - http://www.jag-lovers.com/cgi-bin/majordomo
Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php