TECH INSTALL FABRICATE UPGRADE
(TPS) signal to work properly. All EFI
systems are designed to include a TPS,
so your carbureted engine will need this
sensor. Luckily, several companies offer
a simple conversion that will work with
any 4160 or 4150 Holley carburetor
equipped with an electric choke.
Holley’s kit is simple to install,
using a standard TPS sensor adapted
to follow the primary throttle linkage
movement, but this kit does require a
carburetor using an electric choke. If
you have a Holley without a choke,
you’re still in luck. Innovate Motorsports
and HGM Electronics both make nice
conversion kits that work on the Holley.
HGM is the company that makes the
very nice CompuShift controller for the
electronically controlled overdrives. In
fact, the HGM AccuLink is designed
to work with Holley, Q-jet, and the
Edelbrock carburetors.
This TPS can also be used for data
logging for autocross racers who want
to look at throttle position on track
through the course. But the majority of
users will want one of these kits just for
the simplicity of establishing throttle
position for an electronic overdrive.- Don’t Get Warped
According to Murphy, a common
Holley with driveability or issues is
over-tightening the bowl screws. This
warps the carb main body especially
near the top of the main body where the
main boosters feed from the metering
blocks to the main body. While the
gaskets are thick, this still causes
sealing problems that can lead to erratic
performance. The best fix is to have a
shop like SMI mill the body. Murphy
has made his own fixture to hold the
main body so he can mill not only both
primary and secondary metering block
surfaces, but also the throttle plate
surface.
Murphy has another tip. Holley
doesn’t machine this surface on all
carburetors, so when you disassemble
your carb, look for a lip at the top of
the primary or secondary metering
block mounting surface. If there is a
step in this area, the surface has been
machined. If there is no step—it has
not and is a good candidate for this
procedure.✦ Murphy
machines all
their carb
bodies to
ensure they are
flat. To prevent
warping,
use care in
tightening the
bowl screws.
The spec is
between 120
and 144 in-lb.✦ In this photo note the Holley in the
foreground has no ledge compared to
the main body on the far right with the
small ledge just above the main metering
block mounting surface (arrow). The
ledge means the metering block mounting
surface has been machined.✦ This is Holley’s
TPS conversion
bolted to a 4160
Holley with an
electric choke.
Holley also has
a kit for Gen
3 Dominator
carbs that is very
compact and bolts
directly to the
baseplate.
✦ HGM’s AccuLink
is a very slick
stainless steel
conversion kit
that adds a GM-
style TPS sensor
to all popular
Holley, Q-Jet, and
Edelbrock carbs.
50 classictrucks.com