If you are looking to fit electronic ignition - see below to an article I prepared for a TR Club.
If you buy an Accuspark type it is similar but you have to remove the distributor complete - knock out the gear drive to fit a small spacer ring & reassemble - then fit back in.
Fitting Electronic Ignition to a TR7 Delco Distributor.
There are now a couple of types of Electronic Ignition Units which fit under the distributor cap instead of units which are external & quite large.
Having decided to end the skinned knuckle job of adjusting the old points, I chose a PerTronix Ignitor MR-LS2 which is suitable for the TR7 D302 Delco Distributor.
It chose to buy the kit via the USA from Retro Rockets who supplied the unit from a warehouse in the UK & it was delivered within a week. This worked out 30% cheaper than if bought in the UK at £76.00p delivered -subject to currency fluctuations, which includes UK VAT.
http://www.vintageperformance.com/retro ... gnitor.htm
The Unit can be purchased easily from the UK supplier.
http://www.aldonauto.co.uk
The kit consists of an Electronic Unit, base plate & various screws / bolts. I found it very straight forward to fit & my local Classic Car Specialist who specialise in old Jaguars told me they only fit this kit & has had 100 % reliability.
This type of unit has the advantage of being able to be fitted without removing the distributor from the engine, other types available, which are cheaper, require the distributor to be removed & partially stripped down.
Tools required are
1. 7/16â€AF ring spanner which has to be cut down in length to be able to fit in the restricted space
around the distributor bolts or preferably the correct service Tool to loosen the distributor
bolts. I was luckily to be able to borrow this Service Tool . My advise even before starting the
job is to check that the bolts will loosen off & the distributor will rotate.
2. ¼ “AF Spanner to fit the Electronic unit to the supplied base plate.
3. Set of feeler gauges & screw drivers.
4. Strobe Timing Light. Available cheaply in the Internet at £16.00p
5. Recommended new Distributor Cap & Rotor again a service item, you might as well fit.
6. Spade Connectors Male & Female (Red) plus Scotch Connector ( Blue) to fit the wiring.
a) Disconnect the Battery & remove the heater air scoop above the Distributor.
b) Disconnect the rubber pipe from the inlet manifold which goes to the Brake Servo to allow more working space.
c) Remove the Vacuum pipe from the Distributor & the rubber breather pipe to the rear carb to allow more working space.
d) Remove the Distributor Cap from the Distributor but do not pull off the Spark Plug Leads although the centre coil lead can be removed to allow more working space.
e) Remove the Rotor screws 2 off – the rotor has a square & round pin on the underside so only goes on one way.
f) Remove the Condenser & points – keep them as a backup with all the screws. Have a few bits of blue tack ready to stick onto the screws in case they drop off the screwdriver, which will save you crawling under the car looking for them.
g) Ensure the earthing wire which is secured under the condenser bracket is reattached.
h) Clean the internals of the Distributor.
i) Follow the wire which comes out of the Distributor hole ( black / white colour ) which goes to the –ve side of the coil. It should go to a connector in the engine bay & then go to the tachometer then back to the coil. Disconnect this wire & remove the section of wire to the Distributor. I reused the grommet for the wire & used a drill to make the centre hole in the rubber to allow 2 wires to be pushed through. The new grommets supplied with the kit were a touch loose for my taste.
j) Attach the new base plate to the Distributor with the 2 new supplied screws.
k) Loosely place the Electronic unit on the 2 studs on the base plate & mark the centre position of it – then remove again this allows you to turn the crankshaft to have one of the distributor lobes to be opposite the Electronic unit. This was easier when using the feeler gauge to set up a 10 thou’ gap later on.
l) Fit & secure with the 2 supplied nuts & washers the Electronic Unit to the base plate. I have a small pen shaped magnetic pickup which was handy to place the small nuts onto the studs of the base plate as the nuts are really small.
m) Place the feeler gauge between the lobe & Electronic Unit & tighten the 2 nuts using the ¼ “ spanner producing the correct gap.
n) The Red & Black wires on the Electronic Unit are placed through the hole in the Distributor & grommet.
o) The Black wire – attached a male Spade connector to the wire once fed through the distributor grommet & connect to the female connector for the wire which goes to the –ve connection of the coil / tacho.
p) From the Ignition switch inside the car, trace the white wire which is the 12 volts switchable supply & can be found easily without removing the Steering Column cover – place the scotch connector to this wire & a length of wire into the other side of the scotch connector to run the wire to the red wire of the Electronic Unit via any blanking grommet in the engine bay. I used spade connectors to allow easy connection of the wires & removal if required.
q) Depending on how you want the wiring to look – I fitted cable protection sleeves to the 2 wires from the distributor so no coloured wires were visible giving an original look.
r) Fit the rotor to the Distributor & fit the Distributor cap plus attach the coil lead.
s) Attach all the rubber pipes & and vacuum pipe to Brake Servo.
t) Connect Battery & start the car.
u) You will find the timing is a bit out – you will have to rotate the distributor slightly
v) Recheck timing & adjust further to the correct 10 degs BTC at idle as per Manual.
w) When loosening the distributor bolts – I removed the distributor cap again & the Servo Hose to give better access.
x) Go back to the wiring, insulate tape the connections or use heat shrink tube, secure the wires in the footwell & inside the engine bay.
y) Refit the heater air scoop above the Distributor.
z) The kit comes with full fitting instructions.
Time Scope.
a) To remove old points & condenser – 30mins
b) To fit new Electronic Unit – 30 mins
c) Wiring up - 30 mins
d) Checking / adjusting timing – 30 mins
e) Tiding up wiring – 30 mins
f) Cup of tea – 30 mins