Electric Choke Conversion

An electric choke kit is made by Holley (part number 45- 223) to replace the manual choke. The kit supplies the following parts:

a) short black earth lead,

b) long red (sometimes black) 12V positive lead, c) thermostat housing gasket

d) thermostat housing clamp e) thermostat housing assembly f) choke housing assembly g) choke link

h) fast idle cam lever i) fast idle cam lever spring j) choke housing gasket k) choke link retainer l) choke housing screws m) fast idle cam lever screw

n) thermostat housing clamp screws To install the electric choke kit:

a) Remove the carburetor from the vehicle.

b) Remove the three choke housing screws securing the manual choke housing assembly to the main body. Remove the choke link retainer from the choke link and the manual choke backing plate. Keep the retainer for use at a later time.

c) Remove the fast idle cam lever screw. Remove the fast idle cam lever and fast idle pickup lever and fast idle cam lever spring. Retain the screw, spring, and small pickup lever.

d) Pull the choke housing gasket off and discard it. If the choke vacuum passage has been lead-sealed, carefully drill through the lead (with a drill in a hand chuck) then pick out the hollow ball. Thoroughly clean the mounting surface of the gasket. Blow compressed air through the passage from the bottom of the throttle plate up to make sure the passage is free of blockages. Air should exit from the choke passage.

e) Use the new fast idle cam lever from the kit and the screw, spring, and small pickup lever retained above, as

shown in the figures below. Assemble the parts onto the throttle shaft.

f) Moisten the cork choke housing gasket provided in the kit. Attach it to the vacuum passage hole on the choke housing assembly. Insert the choke rod through the hole in the lever on the back of the choke housing. Make sure the fast idle cam is above the choke rod. Use the fastener clip retained above to secure the rod to the lever. Position the choke housing assembly to the carburetor main body. It will help to open the throttle slightly to clear the fast idle lever away from the fast idle cam assembly. Note that on most applications, the original choke link will be used. However, on certain carburetors the new choke link supplied with the kit may have to be used.

g) Using the three equal-length long choke housing screws from the kit, secure the choke housing assembly to the main body. Manually operate the choke plate by moving the bi-metal pick-up lever on the front of the choke housing assembly. The choke plate should move freely. If not, check the choke linkage to make sure there is no binding and that the fast idle screw is in alignment with the cam on the back of the choke housing.

h) Install the new thermostat housing gasket onto the thermostat housing.

i) Install the thermostat housing and thermostat housing clamp. Install the clamp so it bows outward from the housing as per the image to the right. Ensure the bi-metal pick-up lever (in the housing) fits into the loop on the bi-metal spring. Check this by turning the housing in both directions. The choke plate should open when rotated clockwise, and it should close when rotated counter-clockwise.

j) Using the three equal-length short thermostat housing clamp screws from the kit, fasten the clamp and thermostat housing to the choke housing assembly. Tighten it enough to hold the thermostat housing in place, but still allow it to be rotated.

k) Rotate the thermostat housing until the mark on the housing aligns with the index on the choke housing assembly. Tighten the clamp screws so the housing cannot rotate. Do not block the fresh air intake.

l) Correct polarity must be observed when connecting the electric choke wires. Connecting the (+) lead to earth and the (-) lead to a 12V source will result in a direct short and could cause a fire. Use the shortest wire from the kit to connect the bayonet end to the thermostat housing negative terminal marked (-). Ground the eyelet end to the carburetor. Do this under a screw securing the choke housing assembly to the main body.

m) Remount the carburetor on the vehicle. Connect the long wire from the kit to the thermostat housing positive terminal marked (+). Run the other end of the wire through the firewall using an existing grommet. Connect is to an ignition activated 12V source so that the choke cap only gets voltage when the engine is running – for FB/EK Holdens, this is the from the fuse panel (located under the dash on the driver’s side) via the 15 amp turn signal/heater/backup fuse (the lower one on the picture to the right) at the back of the panel. A blown choke fuse will disable the heater fan, indicators and reverse lights (each of which were either options or standard on FB and EK Holdens). The choke

power lead will require a female spade connector on the end to connect onto the male terminal blade at the rear of the fuse panel (a simple push on fit as the male terminal is already present in all FB/EK Holden fuse panels). It is recommended that insulated terminals are used, as many of the FB/EK wiring terminals are bare, and easy to short. Double check with a voltmeter or test light that the choke only has power when the ignition is on. Note that it is not recommended to use the 12V side of the coil for the power source, as it will result in unacceptable choke operation, and could cause engine misfiring, resulting in possible engine damage. If the vehicle has an aftermarket oil pressure switch (for example driving an electric fuel pump), it would be even better to route the power through that switch – that way the choke only gets power once the engine has fired (and has oil pressure), and does not get power (and start opening) if the vehicle is hard to start and cranking for a long time. n) Start the engine, allowing it to reach operating temperature. Manually

advance the throttle to just off idle. Push the fast idle cam up, so the fast idle screw is on the top step of the cam. This fast idle speed should be set to 1500-1600 RPM. Shut down the engine, and hold the throttle in the wide-open position to expose the fast idle screw below the choke housing. Use a small ¼” open-end spanner for adjustment, turning the screw clockwise to increase the RPM or counterclockwise to decrease the RPM. Start the engine, and recheck idle speed.

o) Choke tuning adjustments are listed below. After making final adjustments, start the engine and make sure the choke plate opens completely.