After 20 years a P6 again finally a V8 automatic. With work that is.....

today I worked on the Rover. I fitted the manifold with the gaskets althought the surfaces looked pretty good. Butr the fact that I didn't really change anything, I put in the gaskets. It is airtight know and runs nice!!
But I hav e a question! Lasttime when I was working with the backlights I turned on ignition without starting the engine. The ignitioncoil got very hot! I think hotter than it supposed to do! Whaty can be the cause of this? The engine has changed and I think the ignition as well. Could it have some trhing to do with a coil needing a balast resitor in the wiring and that tyhe previous owner didnot hook up this wire? Or is it something else?
What coil is advised? The coil which was on the Rover when I bought is was a BOSCH 0221 119 027.
This first coil was ruined I think by the fact that it was left on ignition for a week or so until the battery died....
The present coil is only starting the car at the very and of the starting cycle. When youy let go of the key at the very end the engine "jumps" on. This is what the Bosch also did after the week after the ignition had been on.....
 
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If you leave the ignition on without running the engine and the points are closed then the coil will get very hot. Basically you are giving the coil a supply, and with the coil earthed it ends up acting as an electric heater. Leave it like that for too long and the coil can explode.
 
But why is it then that the coil appears to have not enough "sparkingpower"to get the engine to run? Of course I will avoid ignition on when not running the engine from now on but what to buy as a replacement? What coil commonly known as a good coil?

I don know if the points are closed for it has electronic ignition from Lucas....
 
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PepijnWK said:
The present coil is only starting the car at the very and of the starting cycle. When youy let go of the key at the very end the engine "jumps" on.....
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That sounds like you should have a ballasted set-up. Your coil is not getting to full power because the battery voltage drop when cranking is too high to fire, but at the moment you stop cranking, the voltage to the coil increases and this supplies the required power to fire correctly.
 
unstable load said:
That sounds like you should have a ballasted set-up. Your coil is not getting to full power because the battery voltage drop when cranking is too high to fire, but at the moment you stop cranking, the voltage to the coil increases and this supplies the required power to fire correctly.
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Yep, my guess is the ballast resister has died or the contacts in the starter solenoid have failed.
 
unstable load said:
That sounds like you should have a ballasted set-up. Your coil is not getting to full power because the battery voltage drop when cranking is too high to fire, but at the moment you stop cranking, the voltage to the coil increases and this supplies the required power to fire correctly.
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that could be fixed by a better battery?
 
sdibbers said:
Yep, my guess is the ballast resister has died or the contacts in the starter solenoid have failed.
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ballast resistors can die? Can I do without the resistor and should I change then? The startermotor cranks good could the solenoid have anything to do with the actual starting of the engine while the startermotor cranks fine at high speed?
Battery was full by the way....when I changed the ignition coil the problem seemed oiver but has returned...... it now "eats" the coils.....itr looks like..
 
Thanks for the answers guys! I am not experienced with the electronics with ballastresistors en so on. My question my seem stupid. But I would really like to understand what is going on!! not knowing the exact setup of my car does not help!! I know it is a 1976 P 6 with a SD1 engine and a Lucas electronic ignition. Not sure what type though...I have to check that. But car is 45 minutes driving away...
But last sunday it ran and sounded smooth and quiet!!!! Starting is to be improved however !!
 
My understanding is, with a ballasted ignition system the coil is supplied with a reduced voltage when the engine is running, a coil compatible with a ballasted system is needed.
When cranking the coil is supplied with full 12v via either a wire from the solenoid if separate or from the starter motor if combined.
If the car starts only at the moment the key is released then it sounds like the coil is not getting the 12v 'shunt' that only occurs during cranking, therefore I would be looking to see if the coil has still got its 'shunt' wiring between it and the starter by checking with a multimeter the wires between coil + and starter for continuity.
I had this exact same problem on another car and it turned out the 'shunt' wire had fallen off the starter motor.
 
A shunt wire in the Rover is that a single wire between the + and the starter?
I do not know if the car ever ran normally in this setup. What read is that there are ignition coils 6v and 12 V with or without restors, there are electrnic ignitions als with ballast resistor and without. And I do not know what I exactly have now and how to couple things together......there is a challenge for me!
 
cobraboy said:
My understanding is, with a ballasted ignition system the coil is supplied with a reduced voltage when the engine is running, a coil compatible with a ballasted system is needed.
When cranking the coil is supplied with full 12v via either a wire from the solenoid if separate or from the starter motor if combined.
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From here...
Ignition Systems

Originally, all ignition systems did not have a ballast fitted which meant that the ignition system used a 12v coil with a 12v feed from the battery via the ignition switch. Such a system works fine when an engine is running, but problems can occur when starting the engine. The starter motor draws a huge current from the battery leaving less energy to create a spark across the spark plugs. The result is a weaker than normal spark which is not ideal for starting an engine. This problem is worsened by colder temperatures and/or a worn starter motor which will draw even more energy for starting and leave even less energy for sparking. To overcome such a problem, ignition systems were changed to run a lower voltage coil (usually 9v), and these coils could still give the same output as the original 12v coils. In order to run such a coil, the 12v ignition feed runs through a ballast, reducing it to 9v at the coil. To assist starting, a 12v feed (usually from the starter) bypasses the 9v ignition feed, giving the 9v coil a 12v feed. The result is a better than normal spark which is ideal for starting, particularly on cold damp mornings. As soon as the engine has started, the 12v feed is cut and the coil will run on the 9v ignition feed.
 
PepijnWK said:
A shunt wire in the Rover is that a single wire between the + and the starter?
I do not know if the car ever ran normally in this setup. What read is that there are ignition coils 6v and 12 V with or without restors, there are electrnic ignitions als with ballast resistor and without. And I do not know what I exactly have now and how to couple things together......there is a challenge for me!
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On my 1972 series 2 P6B there are two wires going to coil + joined in a single lucar connector, both are white with a yellow trace, one is thicker than the other. One will be a ballasted feed and one will supply 12v on cranking.
I do not have time right now to check the wiring diagram to see where the 12v feed comes from.
I suspect it will come from the starter, I will check later.

If you have an SD1 motor and electronic ignition then it is possible the whole Lucas Opus system was transplanted and you have a ballasted ignition system and it is also possible that a 12v shunt feed was never incorporated in the change.
You may have to do some testing with a meter to ascertain what system you have, what coil you have and if it is getting 12v on cranking.
 
Well thanks for your replies!!I now understand more of the meaning of the resistor wire and so on. Now I have to figure out what kind of a system I have to solve the problem with only starting at the end... The theory of a non existing resistor(wire ) bypass the shuntwire as you called it, seems plausible! But I am not sure what syustem I have.....
The problems started because of the fact that the ignition has stayed on for over a week...... what could be damaged that way? the coil obviously but is there more that can be harmed by this ignition beiing on for so long?
 
If it helps I found my ballast is not a stand alone resistor, but a white/pink wire, with the yellow/white as mentioned above at both ends. It starts at the firewall and then stops just before the coil to go back to yellow/white. I had a whole other issue which prompted me to find this out...
 
Rob1 said:
If it helps I found my ballast is not a stand alone resistor, but a white/pink wire, with the yellow/white as mentioned above at both ends. It starts at the firewall and then stops just before the coil to go back to yellow/white. I had a whole other issue which prompted me to find this out...
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That’s normal on P6’s. The resister is hidden in the loom.

As to the ignition being on the coil is possibly toast depending on if the points happened to be closed. It’s unlikely the rest of the system is damaged apart from the ballast resistor, that may have burnt out under the same circumstances.
 
Today I made a lot of progress!! Almost all the lights are working now! That was a puzzle because the previous owner used his own wire in two colours black en red but I fount red wires attched to ground and to 12 v same goes for black ...... Well al is sorted. correct colours used and extra obsolete wires are removed. The exhaust is now in place and the mounting rubbers in place.
Brakes are all bled, master cylinder rebuild ,the brakeservo also rebuild. Brakes are fine now!!!
What does not work are reverse-lights! I disconnected the green wires from the Inhibitor switch and voila the white reverse lights lit up. So the inhibitor switch of my BW65 is broken.
I understand they are not repairable.... is that correct? If not a new one is to be ordered...

so almost ready for the Dutch MOT!!
keep you posted
ignition stiull has to be sorted though....
 
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Now I am trying to fix the iunhibitorswitch. I do not think i will have succes but I will try anyway. Getting the switch of was a pain! althoug it is plastic it is stuck due to the rust on the rod it is mounted on.
First I removed the four wires than I pried with a screwdriver for about 10 minutes until it came off...... For next time first use penetrating oil!!!
drilled out the aluminium rivets and here al all the parts:

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offcourse something went not as planned and broke off:

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oin the left the broken piece.... I will figure out how to fix this and reassemble the switch......

Why is a replacement so expensive.........
 
Well, done some handcrafting:

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on the bench it works..........
I am curious if it will work on the car!!!
 
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