Electronic Distributor Conversion
with Instructional Video
For Throttle Body Injection operation, it is
necessary to convert the point style distributor to an electronic unit. This can be done via one of the two options that follow. In addition
to the distributor conversion, you'll need to upgrade your coil to
one of the ones listed below.
Option 1 (Preferred Method)
- Lucas Conversion Kit from Patton Machine
These instructions cover an original Lucas
distributor conversion to electronic operation with timing controlled by
the ECM. This is the preferred method as it will provide complete ECM
control and ignition mapping for you car.
Look over the following procedure and if you aren't confident
doing it yourself, I will gladly do the modification for you. The cost
for the Lucas distributor kit is $124.99. If you would like me to do the
conversion for you, send me your distributor and the cost will be an
additional $50.00 plus return shipping costs.
For a fully functional TBI system your original Lucas distributor needs
to be converted from a contact point type to electronic. The magnetic
pick up assembly provides a steady timing signal to the ECM to monitor
engine RPM. For use with the TBI conversion, both the vacuum and
mechanical advance will be disabled. What we are about to do can be
reversed should you ever decide to go back to original equipment, not
that you ever would.
In addition to the instructions below there are two
videos at the vey bottom of this page.
||With the engine at Top Dead Center,
remove the distributor cap. Make note of the rotor's
position (should be pointing toward #1 plug wire); do not
turn the engine until the distributor has been reinstalled.
Working on a bench with a vise makes things much easier. If
you have a mechanical tachometer remove the cable by
loosening the knurled nut on the side of the distributor.
The wires need to be labeled and disconnected. Remove the
bolt from hold down clamp at the base of the distributor.
Pull out the distributor with a twisting motion. Lightly
clamp the bottom section of the distributor shaft in a vise.
||To remove the breaker point plate
you will need a small Phillips screwdriver for the two
little screws on the plate. After removing the two little
screws, swing the plate up and over the center post pivoting
on the spring linkage of the vacuum advance. Reach in with a
small flat blade screwdriver and slip the vacuum spring
linkage off the post. You should now have the breaker plate
||Grab the upper portion of the shaft
with the cam lobes and see if it will rotate slightly on the
shaft. This rotation is controlled by the weights down
inside the housing. Now remove the screw in the center of
the shaft with a flat blade screwdriver. Does the shaft lift
slightly before the springs get tight? If not, the two
shafts are probably rusted together. Free up these parts
using a combination of penetrating oils and perhaps gentle
heat, (be careful as the tach drive gear is plastic).
||If the shafts are free to rotate,
using a small flat blade screwdriver reach down inside and
disconnect the two springs. Careful not to harm the springs
if you may someday want to restore the distributor to
original specs. With the springs disconnected the upper
shaft will simply lift out. The weights are no longer used
so set them aside.
||The removed upper shaft will look
like the photo.
||Shown here is the new shaft and
reluctor assembly. It is a precise fit onto the spring
posts. NOTE: IT IS DIRECTIONAL AND WILL ONLY FIT WHEN
ALIGNED PROPERLY! You may need to rotate the assembly 180
degrees for proper alignment.
||It should be a sliding fit with the
spring posts sticking up roughly 1/4" above the plate. If
the fit is too tight due to variances in the spring posts
you may need to open the drive plate notches ever so
slightly with a file. It's not time to actually install the
shaft assembly now so set it aside.
|| The distributor housing
requires a slight adjustment to allow the pick up assembly
sufficient clearance. The red arrow shows a stanchion that
needs to be shortened by 1/4". The best tool I've found for
the job is a Dremel tool with a 1/2" sanding drum. Grinding
wheels should be avoided as they load up with the removed
aluminum. A burr on a die grinder or even a moderate to high
speed drill can also do a nice job.
||Shown is the stanchion trimmed back.
And yes it's a different distributor but the result is the
same. Be sure to blow out the housing to remove the dust
||Shown here is the magnetic pick up
mounted to a stainless plate. The red arrow highlights a
screw used to adjust the air gap between the pick up and the
ridges of the reluctor. To install this assembly first set
the reluctor in place and engage it's drive plate over the
pins. Then lift it slightly to slip the pick up assembly in
place. Carefully tighten the two screws that hold the plate
to the housing while rotating the distributor shaft checking
there is no interference between the reluctor and the pick
up. With the shaft assembly back in place install and
tighten the screw in the recess at the top of the shaft. You
may need to loosen the adjustment screw to increase the
|| Looking good. The red arrow
highlights the air gap between the reluctor and the pick up.
It will vary a few thousandths as the distributor shaft is
rotated. Using a feeler gauge set the width of the smallest
gap to 0.006" by loosening the adjustment screw and pivoting
the pick up. Carefully tighten and recheck the air gap. If
you can't get sufficient clearance it may be necessary to
remove a bit more material from the housing as you did when
trimming the stanchion. Before reinstalling the distributor
put the rotor on and snap the dist cap on. Again turn the
dist shaft by hand and check that there is no binding or
rubbing. Install your new electronic distributor!
|The red wire from the
pick up goes to the spade on the module marked "N". The
black goes to the spade marked "P". If you are connecting to
an AFI harness it's black to black and red to clear.
for use with the TBI conversion using the converted distributor and
ignition module that is part of the kit. See Pertronix note below
NAPA coil # MPE IC88SB
MSD Blaster coils 8200
Pertronix 40001, 40011,
Crane PS20 or PS40
NOTE: It's always a good
idea to have a fire extinguisher handy when starting the
car for the first few times. Turn on the key and you'll hear the fuel
pump run and then stop. Check for leaks at all fuel line connections.
Setting the timing while still running
You can run the
car using the electronic distributor while still running on carburetors.
To set the timing make the connections to the module BUT
first disconnect the single pin connector near the module. Loosen the
distributor locking clamp so it can be rotated with a little bit of
friction. Position the distributor approximately in the same position as
it was before the conversion. The cap and plug wires should be installed
as originally. Connect a timing light to "1" spark plug. Be careful as
the engine is able to start when cranking in this condition. Matter of
fact once the timing is set it will run nicely on the carbs. While
cranking the engine on the starter or at idle, set the timing to 14
degrees before top dead center. Lock the distributor down. If the ECM is
installed and powered, you can connect the single pin connector which
will allow the ECM to control timing even though the fuel injectors have
not yet been installed.
Setting the timing when running fuel
If the engine has
been running with the converted distributor on carburetors (directions
above) it requires no further adjustment.
Much the same as
"Setting the timing while still running on carbs" but you will set the
timing while the engine is spun over by the starter.
DISABLE THE FUEL PUMP OR DISCONNECT THE INJECTORS WHEN SETTING THE
TIMING FOR FUEL INJECTION OPERATION! We're NOT trying to start the car
yet. We just going to set the timing by cranking the engine.
If the engine has
not yet run on the converted distributor a backfire is possible so
disabling the fuel supply will allow timing to be set safely.
Disconnect the single wire connector near the ignition module. Using a
timing light while cranking the motor with the starter rotate the
distributor until the timing is set to 14 degrees. If you don't have a
remote starter switch, you'll need a helper to turn the key while you
set the timing.
To complete the distributor installation, lock down the distributor and
reconnect the single wire connector. Make sure you enable the
injectors or fuel pump that you previously disabled. Providing
the ECM is connected to it's sensors and powered up, you are now running
a programmable computer controlled electronic ignition system! With a
timing light you can check timing at various RPM's. For instance, just
above idle speed, timing should jump out to about 20 degrees.
When driving if you hear pinging the timing is probably too far
advanced, drop it back a couple of degrees. Excessive pinging can damage
the engine. From this point on the timing should not require further
adjustment and, unless someone is really looking, the conversion is
really hard to spot.
Option 2 - installation of a
Pertronix Ignitor Electronic Ignition
This aftermarket component is readily available
and typically costs about $100. With this option you don't have the advantage of
electronic ignition mapping as performed by the Engine Control Module
(ECM). For that capability you'll need to install my conversion kit as
detailed in Option 1 above.
Please follow their directions for setting the
NOTE: If you are running a
Pertronix ignition, please check with Pertronix for the proper coil
noting that there are two models of Pertronix Ignitor. The
original Ignitor as used with most British cars requires a coil or
coil/ballast resistor combination of at least 1.5 ohms while the Ignitor
II has current limiting abilities
The following two videos walk you
through the conversion process for making your Lucas distributor an