No spark at plugs - Lumenition ignition

#1
Hi guys!

Last weekend my Rover stalled on me... Had driven for about 10kms without any problems, when the car suddenly died. No spluttering or anything, just gone at once. This happened to me some 4-5 times earlier as well, but at those times the car started right up again! This time I wasn't so lucky.

Checked the car and found that my HT lead had spark, but I didn't have any spark at the plugs. Called the road service, which came by and diagnosed a possibly faulty rotor. Since that's an easy fix, I had them tow the car back home. I ordered a new rotor, but... nothing! Spark at the HT lead, but nothing beyond that.

My car has the following setup. 4.6L V8 out of a Range Rover with a Lumenition Optronic ignition. I recently changed the distributor cap, apart from that the rotor and the chopper of the lumenition are new. I ordered two new rotors and have tried both. I tried different spark plugs, and different spark plug leads...

I called the company that delivered the rotor etc (Smink, P6 specialist in The Netherlands) and discussed the case. He thought it might be the distributor cap, even though it's essentially new. He doesn't suspect the Lumenition power module, because I have a spark at the HT lead. He couldn't help me any further over the phone, which I fully understand.

I will order a new distributor cap (bummer that regular shops are closed now) because it won't hurt having a spare and they're cheap. If that doesn't fix the problem, is there anyone out there with some other ideas?
 
#4
I’d be checking the spring loaded carbon centre “button” which needs to make contact with the rotor
Jim
Good thinking, already did! Haha! :) It makes contact, even checked if it made contact with a little dot of grease (which I cleaned up afterwards). Thanks for the input, all ideas are welcome!
 

corazon

Well-Known Member
#5
Have you got the old cap to test?
There’s spark from coil going to the cap but not getting distributed any further..Are the rotor and chopper both moving freely with engine rotation?
Checked the earths?
 
#7
Have you got the old cap to test?
There’s spark from coil going to the cap but not getting distributed any further..Are the rotor and chopper both moving freely with engine rotation?
Checked the earths?
Sadly no, the carbon centre snapped off in that one! So can't check with an old one... Yes exactly, there's power going to the cap and it ends there. The rotor and chopper are moving. Have quickly, visually checked the earths. Everything is still connected. Would be odd, losing the earth so suddenly? But I will investigate further as soon as I'm back with the car! Will be somewhere next week after my shifts at work end. :cool:

Do you a multimeter you can test the dizzy cap with the meter?
I do have a multimeter. How does one test a distributor cap? :)
 

sdibbers

Well-Known Member
#10
Sadly no, the carbon centre snapped off in that one!
You can probably remove the button with its spring from the new cap and fit it to the old one. That might give you something to test with.
You mention a spark at the king lead from the coil to the cap. How strong was it? If the spark is weak you could have it to there but not enough to the plugs after the rotor arm.
I would also look inside the cap for evidence of arcing causing cross firing and erosion of the contact on the arm.
 
#11
It's a possibility that the new rotor arm is faulty as well. Have you tested it, and where did you buy it from?
I get your thinking, woudn't be the first new piece to arrive malfunctioning! However, I bought two. That would mean both of them are faulty. Got them from Smink, a Rover P6 specialist in The Netherlands. :)

You can probably remove the button with its spring from the new cap and fit it to the old one. That might give you something to test with.
You mention a spark at the king lead from the coil to the cap. How strong was it? If the spark is weak you could have it to there but not enough to the plugs after the rotor arm.
I would also look inside the cap for evidence of arcing causing cross firing and erosion of the contact on the arm.
Binned it when I got the new one... I ordered a new cap, which should come in in a couple of days. The spark was decent, could see it from the drivers seat (HT lead on the air filter on top of the carb) whilst it was in full sunlight. I'll test the new cap when I get, and report back after that. Thanks for your time gentlemen!
 
#12
I would love your input again, as I've already learned something so far! So thank you guys. :)

Had a chance to check the car over today... Here's what I measured, saw and learned.

- 12.2 volts at the battery, 11.9 volts at the coil. Seems healthy.
- Spark from the HT lead is yellow but will reach about 3cms through air, which seems healthy to me? Would prefer a blue spark though... Had someone else sit in the car this time, so got a close look now.
- The distributor cap measures around 9 Ohm, and is therefore not broken?
- Different sparkplug wires and the HT-lead measure around 8-13 kOhm and are therefore functioning properly?
- When I looked closely at several ground spark plugs whilst cranking the engine... I SAW SPARK. It wasn't massive, but spark nonetheless!

Which personally leads me to two possible conclusions:
1. I have a spark, but it's not strong enough (coil, battery going flat?). The road service guy concluded I had no spark, and he probably was right so I'm a bit baffled to why the car won't start? I will change the distributor cap tomorrow (I have a new one anyway) and will hook some jumper cables up to the car for some extra juice... If it won't start, I don't really get it anymore, haha!

2. It's a fuel problem after all and the diagnosis of me and the road service guy was wrong. My car solely runs on LPG, which I know nothing about. My spark plugs are grey-ish and even after several starting attempts very dry. Is this a normal situation when you're running a car on LPG, or do I have a fueling problem? I can't run the car on petrol, there's no petrol tank in it and it's a special 100% LPG setup. Are there any easy tests on LPG systems? At this point I'm considering searching for a classic car shop that knows about LPG and let them sort it out. But it would be better, more fulfilling ánd cheaper if I could do it myself! ;):D

Thanks for any further input you guys, really appreciate it!
 
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SydneyRoverP6B

Well-Known Member
Staff member
#13
Hi Thijs,

The standard silver Lumenition power module (as opposed to the black version) must be set up with a ballasted coil, else the power module will be permanently damaged. The voltage at your coil suggests that this is not the case.

When my Lumenition power module was failing, it would do exactly as you describe, the engine would cut out instantly. Wait a while and it would restart as if nothing was wrong. Then sometime later, the scenario repeats. When my power module was failing, I too had a spark from the coil, but the engine would not start. I changed the power module and problem solved. That was 5 years ago and not a peep since!

My advice, change your power module and be sure to use a coil with ballast resistor.

Ron
 
#14
Hi Thijs,

The standard silver Lumenition power module (as opposed to the black version) must be set up with a ballasted coil, else the power module will be permanently damaged. The voltage at your coil suggests that this is not the case.

When my Lumenition power module was failing, it would do exactly as you describe, the engine would cut out instantly. Wait a while and it would restart as if nothing was wrong. Then sometime later, the scenario repeats. When my power module was failing, I too had a spark from the coil, but the engine would not start. I changed the power module and problem solved. That was 5 years ago and not a peep since!

My advice, change your power module and be sure to use a coil with ballast resistor.

Ron
If I look at this thread (which you posted in too! :) ) I read you only need a ballast resistor if your coil has 1.5 Ohm, if it reads above 2.5 Ohm you should be good without one?

Which coil to use with Lumenition ignition module



I'm going to measure my coil later today. Will also try and see if I can get any sign of life from the car with some spray-start. If it coughs/starts I know that I most likely have a fueling problem. If it does nothing, well that quite honestly just leaves the power module since I've changed virtually everything else! Thanks dor your reply! :)
 
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#15
I'm starting to think you might be correct Ron!

Switched the distributor cap for the new one, which of course didn't make a difference. At least I have a spare one now. :) Measured the coil too. 3.1 Ohm at the primairy and 7.8 kOhm at the secondary, no problems there either.

Tried starting the car with a lot of quick start spray. That stuff is crazy flammable. Out of 5-6 attempts I got a bit of a cough and <1 second of running. Nearly nothing. If I really have a fueling issue I'd expect it to run easier and a little longer on this quick start spray. Apart from that, it seems so odd to me that it at first was an intermittent problem ánd most of all that the engine stopped instantly. Can't quite get my head around that being a fuel issue, hás to be electric I reckon! :confused:

Any other thoughts on this?

If I were to order a new Power Module, any companies to recommend? I found two, but will also check with the Dutch P6 specialist...

Spare Silver Power Module for Lumenition Optronic Ignition from Merlin Motorsport

Lumenition electronic ignition power module only

Cheers guys, you've been a great help so far! :cool::D
 
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Ban306

Active Member
#16
I'm starting to think you might be correct Ron!

Switched the distributor cap for the new one, which of course didn't make a difference. At least I have a spare one now. :) Measured the coil too. 3.1 Ohm at the primairy and 7.8 kOhm at the secondary, no problems there either.

Tried starting the car with a lot of quick start spray. That stuff is crazy flammable. Out of 5-6 attempts I got a bit of a cough and <1 second of running. Nearly nothing. If I really have a fueling issue I'd expect it to run easier and a little longer on this quick start spray. Apart from that, it seems so odd to me that it at first was an intermittent problem ánd most of all that the engine stopped instantly. Can't quite get my head around that being a fuel issue, hás to be electric I reckon! :confused:

Any other thoughts on this?

If I were to order a new Power Module, any companies to recommend? I found two, but will also check with the Dutch P6 specialist...

Spare Silver Power Module for Lumenition Optronic Ignition from Merlin Motorsport

Lumenition electronic ignition power module only

Cheers guys, you've been a great help so far! :cool::D
Have you tested the module?
Also what spark plugs are you using?
Are you running a fuel injection system?
 
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SydneyRoverP6B

Well-Known Member
Staff member
#17
Hi Thijs,

I purchased my Lumenition during 2015 from a supplier in the U.K. The two that you list would be I suspect equally as good.
In answer to Ban's first question, https://www.merlinmotorsport.co.uk/files/transfer/technical/doc/optronicinst.pdf

Spark plugs won't be the cause, given I had the same problem and changing the power module solved the problem. It had provided perfect service for some 24 years, so I couldn't be too hard on it.

Ron.
 

Ban306

Active Member
#18
Hi Ron I am not saying it is the cause but I thought that running just on LPG with standard plugs can significantly reduce the life time of the spark plugs as LPG burn rate is hotter and can cause starting issues and misfire. The module could well be faulty but I think you can test them to make sure and also checking you have the correct spark plugs that are happy to run on LPG might help.
Here is a very interesting article
we really do take for granted an actual spark plug.
Spark plugs and LPG | gazeo.com
 
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#19
Hi guys, sorry for the late reply! Bit of a twist to this... Let me explain. :rolleyes:

The guy I bought the car from dropped by last saturday to help me. He installed the LPG system, so he knows it best! Turned it was a bad electric connection to a relais in the LPG system. So it was electric after all, but relating to the fuel!

All good and well, the car ran perfectly and we we're chuffed. When I drove the car home later that night, a completely new problem presented itself. :( It ran good for about 10 miles, but started misfiring after that. Parked it and decided to look at it when it wasn't dark outside. Yet again, the car ran okay for a couple of miles but started misfiring. To a point that it ran on only a few cilinders, and when I put in out of Park (it's an auto) it stalled every time!

At this point I decided that I was done with it. I'm very busy and it's quite stressful at my job at the moment (I'm a doctor, working in the ER right now) so I didn't wan't to spend any more time on it. I had it towed to a classic car shop close to my home. They're looking at it now, I'll post here when there's any progress.

Thanks again for all your input. I learned a lot from this whole ordeal! :) I don't like admitting defeat and always prefer to fix my classics myself. But right now I'm not in the mood to do any more work on the Rover. Escpecially since my dad's Lotus and his BSA need some work too, as do my Moto Guzzi and Royal Enfield. It's a hobby that at least keeps us busy, right?! :p;)
 
#20
I can recall a similar fault with a Company marina 1.3, which broke down like this several times. Each time the breakdown service was called and diagnosed a ' faulty rotor arm' and replaced it. Car went OK after for time until the breakdown would repeat. Old rotor arm looked o be perfectly OK.
Finally the garage that serviced the cat replaced all the ignition in a desperate effort to cure the fault. I left that job 3 months later but the car was going perfectly when I left.
One of the mysteries of life, no mechanic ever came up with any explanation of repeated breakdowns.
Just a thought, this might have some bearing on your breakdown. Marina was standard, 1971 model 1.3L
 
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