10 replies to this topic

[Regers]

Hi, I'm new to this forum so I'll need some help just incase I make a mess of it... I have a fairly standard 1985 998 Mayfair which I've just got finished about four months ago but now its melting the plastic cam follower on the points ?? I have changed the coil, condenser, cap, leads, rotor arm just about everything. The only other thing I can think of is that the car is charging at 14.2 volts at about 1500 revs and 13.1 volts at idle?? I thought I new most things about Mini,s since I've always had one from I was in my twentys but I can now say I'm stuck with this problem. Can anyone steer me in the right direction PLEASE

[79Clubman]

@regers

Put a thin film of grease on the shaft.

Cheers

[lrostoke]

Is the little sponge bit inplace, this should be dabbed with oil, it lubricates the heel of the points

Or get rid of them and fit one of the cheap aftermarket electronic kits. Something around £20

Edited by lrostoke, 13 December 2011 - 06:22 AM.

[Bungle]

with a velman electronic kit costing less than £20 i can't see why anyone would still run points

just switch over to electronic ignition

[dklawson]

As above, make sure the 4-lobe cam under the dizzy rotor has either a thin film of light grease on it and/or that the felt wick is installed and that the wick is very damp with oil.

You changed a bunch of things in the ignition system. In particular, you changed the coil. I wish you had not. Are you sure you bought the correct coil for your ignition system? Please don't say "the guy at the parts counter said....".

There are ballast coils and standard coils. If you install a ballast coil where a standard coil should be used, the ignition system will draw too much current which in turn causes the points to burn, condenser to fail, and eventually coil failure. This can also cause the plastic heel block on the points to melt.

Start by telling us what color the wires are that connect to the coil and which terminals ( + or -) those wires are attached to.

[Regers]

Thanks for all the replys. The problem is not the heel wearing but the heel melting. I've replaced the coil with the original which has been on the car from new!! This is a ballast coil as was the new replacement. I've tried to earthing the dissy and the points base and cleaned below the points themselfs. I see what you mean about the wrong coil through. Where is the ballast resistor? I'll have to look at what colour wires go were? But I cant see how this is starting now when the car has been driving for the last 1500 miles since the total rebuild. Is the alternater putting out too much?, I know all the earths are good to the engine, I've tested them and getting no drop between the battery and the block/dissy. The only other thing I have done is fit an extra fuse box for a rally trip meter and map light but i have disconnected this as well ??
Once again Thanks to you all for the help

Regers

[lrostoke]

I can't see how its electrical, If the heel is melting it must be through friction, if the area was getting hot enough to melt plastic there would be a serious short.

14.2 volts is fine with engine running. I think normal range with no load is between 13.5 and 14.6 volts as a rule.

Regards the ballast resistor its built into the coil live wire. A ballast system will have 2 wires going to coil positive, yellow/white and white/pink it may be white/yellow and pink/white but that combination anyway

Edited by lrostoke, 14 December 2011 - 07:14 AM.

[dklawson]

I agree with Steve. Since you have replaced the coil with one of the same type this should not be an electrical issue. To be sure though, do confirm which wires are on the coil (+) terminal and let us know what you find.

Note that we did mention lubing the dizzy 4-lobe cam either by grease or the oil wick. If that is not done the plastic heels can wear and/or melt due to friction.

[Regers]

What should the voltage be at the + pos side of the coil?? I'm getting around 12 volts when the engine is off ?? I really dont think its wearing the heel out as the melting is at the spring end of the heel. The face of the points are burning quite badly too. I can see the ballast wires, could it be faulty?? The coil is wired +pos switched and -neg to the dissy.

[lrostoke]

See you didn't mention any of that.

Doug's mentioned about the voltage at the coil before it changes on a ballast system depending on the position of the points. It can range from 8 to 12v depending on the position of the points.

That sounds like condensor problems, just cause its new doesn't mean its not faulty. Are all the connections tight, no frayed wires , All the plastic insulators in the right place.
Is the thin earth wire in place between backplate and dizzy body, these can wear also

To be honest though I'd spend £20 and get rid of them..Electronic ignition, no points, no condensor, no parts to wear out.

Edited by lrostoke, 15 December 2011 - 06:31 AM.

[dklawson]

As Steve said, what you measure at the coil will depend on whether or not the points are open or closed. To get a good indication of what is going on, remove the dizzy cap and place a coin between the points. Turn the ignition switch to the run position and use a multimeter to measure the voltage between coil (+) and earth. With a ballast ignition system you should find something between 6V to 9V. For a standard ignition system you should find about 12V. If the points are open (and/or you don't put the coin in place) then you will measure battery voltage on coil (+) regardless of the ignition type. Again, the points must be closed during voltage measurements.

Take another close look at the wires connected to coil (+) and try to determine their colors. Follow them back into the loom if necessary to reveal their original colors. Let us know the colors of the wires and repeat the voltage measurements with the coin and let us know what you found.

If the wire colors and voltages are correct, then it is quite likely to be the condenser as Steve said. Pictures are very helpful if you can post some.