Wiring connections to CB points 1098CC - with update!

[MGFmad]

I have not worked on points for years and I am not sure how I should connect up the wires to the new set of points I have fitted - I did not pay close enough attention when removing the old set

Its the 2 connections onto the spring of the points that I am confused with.

Is it the correct way to fit the permanent wire that comes into the distributor (LT?) onto the spindle first, pushing the circular plastic insulator onto it so that it makes contact with the spring but not the spindle, then mount the condenser wire on top of the plastic insulator so that it doesn't touch the spring or LT wire?

And a further question - I stupidly connected the 2 wires together onto the top of the spindle - would this have blown the condenser? If so it will be a mad dash to try and locate another tomorrow morning as I have the MOT booked for Monday!

[PSL184]

If I remember correctly, it should be spring on spindle first, then capacitor wire then LT wire and insulator down the middle of that lot, secured with nut on top...

[rayofleamington]

spring on spindle first, then capacitor wire then LT wire and insulator down the middle of that lot, secured with nut on top...

or to be pedantic..... it's insulator, then spring arm, then condenser, then LT, then insulator, then washer, then nut.

I stupidly connected the 2 wires together onto the top of the spindle

no harm done - all the points do is connect the LT to ground when closed, then open the circuit when they're opened by the cam. By fitting both wires just under the nut you've just put them both to ground, which is normal but you won't get the 'open' hence no spark.

The condenser is to reduce the arcing at the points, so the wire needs to be connected together with the LT. (the housing of the connector goes to ground when you attach it to the baseplate.

[MGFmad]

Thanks for the info. I refitted the wiring but cannot get the car to start. Really frustrating as it was working perfectly before I decided to fit the new points!

Maybe I am missing something simple. I have fitted the points with a 0.40mm gap, condenser and rotor arm. When I try to start it, the engine spins as normal, if I pull out the choke it goes slower then really slow like its got a flat battery, same thing happens if I put my foot on the accelerator. Then choke back in and it spins as normal.

I charged the battery just in case but no luck.

I took out each spark plug (also new - fitted today) held it to the block and I get a spark at the plugs, I removed the fuel supply pipe and fuel comes through when I crank the engine.

Would a faulty condensor give perhaps to weak a spark to start?

Could there be a coil problem although I get a good spark when holding the HT lead against the block.

Hopefully you can help.

[PSL184]

If you have a spark and fuel then the only other problem that would prevent a start is timing. Did you move the dizzy or have you mixed the HT leads up somehow when changing the plugs... Firing order is 1,3,4,2 ?

[MGFmad]

This is the strange thing, surely it would start with fuel and a spark. dizzy was not moved and I numbered the ht leads, also checked the firing order (as a double check) and the leads are in the 1,3,4,2 order.

Only thing I can think of is the coil is faulty, perhaps using too much power, producing the slow cranking - but its just a wild guess!

[PSL184]

Can't see how that would make engine turn over slowly - that's the weird bit! Is fuel getting through the carb? You say its pumping when you take the fuel line off but is it actually getting to and going through the engine?

[Cam]

If it worked fine before, then it's most likely to be points or HT related. I have had a 'slow' turning engine before when I have mistakenly connected the HT leads to the wrong plugs!

pull the plug leads off and crank again. If it speeds up then make sure that (looking at the dizzy cap) they are connected 1,3,4,2 when rotating anti-clockwise. It's more likely that a couple of conections might be wrong, but I guess it's possible to be 90, 180, or 270 degrees out!

[MGFmad]

Checked again this morning, all leads are in the right order for the 1,3,4,2 firing order (anti clockwise) points gap still 0.4 and checked that power is isolated between the spring and post of the points.

Checked the spark at the plugs again - perhaps not a bright blue, has an orange tinge about it.

Engine spins fast on the starter, pull out the choke and its slows a bit - like its going to fire but then decides not to.

I am wondering if I have damaged the coil by doing the connections wrong to the points originally, (or it has decided to give up!) I am getting 12V output from the LT side of the coil - measured both at the coil and the connection at the dizzy.

And just one final thing - I am assuming its impossible for the timing to now be out as I have not touched the dizzy mounting.

Is there any output test or resistance type test I can do on the coil? apart from testing for a spark from the HT lead.

[bmcecosse]

Maybe it's just badly flooded - take the plugs out and dry them off with a gas torch - and crank the engine with throttle wide open and plugs out for a few seconds - then leave it for a bit. Refit the plugs - and unscrew the hex on top of the SU and let the damper flap about loose. Then - try again ! If it starts - tighten the hex again. You coulkd also try a tow start - I had a highly modified Mini a while back that just WOULD NOT start. Towed it up the road and it started after a few seconds and was fine after that . If still no go - could be hopeless condenser - refit the old one. It won't be the coil.

[MGFmad]

Thanks everyone for your help. It was timing in the end!

My fault though as for all I had taken great care to get the HT leads in the correct order on the new dizzy cap, I had them 90º out of sync. Only discovered when I set the engine to TDC and the rotor arm was at HT lead No 2!

Running well now.

[PSL184]

Well done... Learning is fun

[rayofleamington]

My fault though as for all I had taken great care to get the HT leads in the correct order on the new dizzy cap, I had them 90º out of sync. Only discovered when I set the engine to TDC and the rotor arm was at HT lead No 2!

well done for finding it - that was my next question!
You said you'd numbered the leads and got in right order but hadn't said how you got the start point, so I was going to ask where the rotor arm was pointing at TDC...
I think it's always better if you can find the problem yourself as that way you'll remember for next time ;-) Nothing wrong with asking for advice though!
Now you're nearly there it would be worthwhile to check you spark timing - changing the points / re gapping will affect the timing a little so it's worth to set it up.

[bmcecosse]

Best to mark #1 lead with a little tie-wrap. Then there's no doubt!

[MGFmad]

quite frustrating though, After rebuilding the complete car I get stuck on simple points and HT leads

Fingers crossed for Monday when it gets MOT'd