no spark

[xpress]

i can't see a spark when i turn the engine on the starting handle with ignition on. car not starting. changed condenser. was very careful to put it back the same way it came off. still not starting. fuel pump is clicking only once when ignition turned on as normal and there is fuel sloshing in the tank,

i took a look at the points, they look worn right down so will change those next. any tests i can do with the multimeter, can you tell me where to place the + and - probes of the multimeter if suggesting where to test for resistance, voltage/continuity and what i should expect to see/not see. please explain carefully and idiot proof so i can get this right.

many thanks for your help in getting her started.

[Alec]

Hello Xpress,

you don't really need a multimeter although you could measure the voltage from the coil distributor connection to earth, if your car is still positive earth, + ve lead to earth and - ve lead on the coil + ve or CB, depending on how old your coil is, ideally about 0.2 volts or so, but not more than 0.5 volts with the ignition on and points closed.

When in the above position just flick the points open and you should see a spark at the points if all is well. If not turn the engine to open the points and do the same voltage check as above, you should now have about 12 volts. If you don't the points are connected wrongly.

If you do have a spark then look to the rotor arm\distributor cap\leads etc The fuel pump stops clicking when the carburettor is full so that's normal.

See what you get and report back.

Alec

[xpress]

Thanks Alec.

I don't have a spark at the distributor points. The car is negative earth. The coil is an old Alu Lucas one. Where do I put the probes? Once i know I will measure the points open and closed and report back with voltage and resistance. TThanks Alec

the

[Alec]

Hello Xpress,

just reverse the leads, the distributor wire should be connected to the - ve on the distributor, put the + ve lead on that terminal and the - ve lead to earth.

Alec

[xpress]

checked the plus terminal on the coil with the multimeter attached to ground, ignition on, no voltage.

the plus and minus lucars are the 12v ignition from the switch, right?

checked the little lucar connector on the distributor to ground = no voltage reading on multimeter.

checked the +ve terminal on the coil with ignition off to ground, measured a resistance of 1?

put the car on ignition one, the coil does not warm up.

checked the king lead from coil with screwdriver wedged in and placed on block.

ignition on, cranked with starting handle = no spark.

i checked the voltage of the battery to see if the multimeter was working = 11.76 volts, probably because i have been cranking it too much trying to start it.

BMC, COULD IT BE THE COIL?!!!

[Alec]

Hello Xpress,

did you measure the coil - ve terminal with the ignition on, should have 12 volts approximately, and the same on the + ve terminal if you disconnect the distributor lead from it.
If not then there's something wrong from the ignition switch.

Alec

[xpress]

just went out and double checked.

coil plus and minus from ignition, taken off coil, ignition on and plus and minus multimeters inside lucars = 0.08v
battery condition = 11.88v
coil primary windings, plus and minus probes on plus and minus of coil, ignition off = 3.2 ohm
coil secondary circuit, plus probe inside king lead pin, minus probe on coil: minus 12v ignition pin =
it shows 1 and never moves from 1

[Alec]

Hello Xpress,

if I understand correctly you don't have any supply to the coil. Try a piece of wire from the battery negative to the coil negative and see if you now have a spark? Don't leave this wire on for too long or the coil will overheat.

Alec

[xpress]

hi alec i will try that.

is that a strange reading to get from the secondary output of the coil and the primary negative earth?

could it be a fuse that's blown?

regards

[Alec]

Hello Xpress,

I didn't understand what you were measuring at the king lead? Was it resistance?

The ignition is not fused, the coil and fuel pump are connected to the live side of the ignition switch fed fuse.

Alec

[xpress]

I measured secondary resistance at the king lead. Tried a patched lucar to the negative coil terminal. No luck.

[bmcecosse]

You MUST get power to the coil - or all is lost. Try it with a jumper lead direct from the battery.
I have to say - I've NEVER seen anyone have so much trouble with the Ignition circuit.........it really is very very simple and normally ultra reliable too. Especially the coil!

[Alec]

Hello Xpress,

when you have the lead from the battery to the - ve terminal, go through all the other checks again. Voltage at the + Ve terminal, points open and points closed (distributor connected), should see about 12 v and near zero volts respectively. (Distributor should be connected to the + ve)
I've never measured the secondary winding resistance but I would expect it to be high, primary is abiout 3 ohms I think but you may have to go up a scale or two for the secondary?

Alec

[bmcecosse]

Primary should be 3.2 ohms for a non-ballast system. The secondary should only be tested with a high voltage meter - readings taken at 1 1/2 volts are pretty much useless there......