Loose wire ?/High performance ignition coil
Discussion
I changed my fuel filter yesterday and only today noticed a loose wire from that area. The wire is yellow and goes into a black conector. On the other side of the conector the wire is black. There is no obvious place for it to go, can someone check theirs and advise.
Also I put a Lucas high performace coil in and rather than up the performance and economy, the car missed badley over 3000 rpm, worse when I refitted the original the problem persisted, screwed resistor ?
Help.
Cheers Keith
Thanks Keith
Also I put a Lucas high performace coil in and rather than up the performance and economy, the car missed badley over 3000 rpm, worse when I refitted the original the problem persisted, screwed resistor ?
Help.
Cheers Keith
Thanks Keith
Hi Keith. Sorry but I haven't a clue about the yellow wire. However these cars are very fussy about the coils.
The ignition system uses a "constant energy" system, which in practice is a very low resistance coil (around 0.5 Ohms). This would blow up if you connected it to 12 Volts, so the ignition amplifier regulates the charge into it. In practice this means that you get the same energy in the spark regardless of battery voltage or engine speed.
Lucas part number for the correct coil is DLB198, or Land Rover part number PRC 6574 for the Bosch version.
Good news is that fitting the wrong type of coil is unlikely to have damaged your ignition system, so your misfire is probably due to something else. Is your fuel filter fitted the right way round?
If you can give more details about your misfire then maybe someone can point you to the source. Is it load dependent, or just speed dependent?
Good Luck!
Tel: 01694 720 144
Mob: 07798 582 390
The ignition system uses a "constant energy" system, which in practice is a very low resistance coil (around 0.5 Ohms). This would blow up if you connected it to 12 Volts, so the ignition amplifier regulates the charge into it. In practice this means that you get the same energy in the spark regardless of battery voltage or engine speed.
Lucas part number for the correct coil is DLB198, or Land Rover part number PRC 6574 for the Bosch version.
Good news is that fitting the wrong type of coil is unlikely to have damaged your ignition system, so your misfire is probably due to something else. Is your fuel filter fitted the right way round?
If you can give more details about your misfire then maybe someone can point you to the source. Is it load dependent, or just speed dependent?
Good Luck!
Tel: 01694 720 144
Mob: 07798 582 390
Mark, if Keith has a 350i, then the ignition system would definitely NOT be a "constant energy" system(like a CDI system) and the coil would be around 1.2-1.4 ohms (checked and also in in Steves book). So, is it a 350i? Bit confusing .. (don´t know about the newer systems)
Regarding the missfire, IF it´s a 350i based on vitesse 3.5ltrs, the ignition module is trigged by a inductive unit(coil). That solution is crap (though maybee cheap) as a trigger solution and it will definitely not work together with a high voltage coil since the higher voltage and spark energy will interfere with the trigger(small coil) unit in the distributor and the engine will probably start to missfire due to incorrect pulses to the amplifier. I´m not shure that the trigger amplifier can take a high current coil at all, but that´s another story. Best solution is to REPLACE the standard trigger solution with a Lumentition(optic?) or IGNITOR(hall switch) unit. At least the IGNITOR can take the current of a "normal" 40-50kV blaster.
A +50kV high energy mega coil is probably better suited for a 30PSI turbo engine than a 3.5 rover v8. A better solution, and end result, could be to install a multiple spark system like MSD(6AL etc). Maybee Mark has seen some rover v8´s with MSD´s on the rolling road and if it really makes any differece ?
Hi Bengt
It really is a constant energy system - honest! It comes from the Rover SD1 version of the V8. You can check it by looking at amplifier pack on the side of the distributor, which should be marked "Lucas 9EM Ignition Module".
There was a slightly earlier version (1984) which had the coil strapped to a large aluminium box. The box contains mostly fresh air, and an older GM constant energy ignition amplifier.
Every 350i I've ever seen (and that's quite a few) has this on as the original system. This was also used on the Jaguar V12 which revs to 7000RPM.
Good news is that you cannot blow up a constant energy amplifier by putting an ordinary coil on it. It just can't get enough energy into it to make a good spark.
The system will reliably drive higher output coils, which I have used successfully on some older racers. One example of this is the American "Accel" coil. It is an ugly enormous yellow plastic thing, but it makes a spark like an arc welder!
No I have never seen an MSD on the dyno, so I have no idea whether it is valuable or not. I would be interested to have a look at one though, and I'll happily feed back the results.
I have set up twin turbo motors with the standard ignition system and they work just fine, as long as you use the right plugs and leads. No problem with burn time or energy, so I'm quite happy with it (which doesn't mean there aren't better ones of course).
Remember a similar distributor, coil, and constant energy amplifier are also successfully deployed on the Sierra Cosworth.
More recently I have been using the Omex mappable ignition system (highly rated!) on these type of installations, and you can even program the energy put into the coil.
Lumenition do three different systems, two of which are optically triggered from the distributor, and one is a mappable system. The two distributor systems use an optical pickup, although I have only found a fitting kit for the earlier Opus distributor. One is a normal system, and the other is also a constant energy system. I have set up and tested all of these systems.
In practice the standard constant energy system does not seem to pick up any interference, and I did monitor it very carefully with an oscilloscope. This is even true on forced induction motors under heavy load.
I hope this doesn't come across as heavy-handed or know-all - it isn't meant to!
>> Edited by Mark Adams on Sunday 8th September 00:39
It really is a constant energy system - honest! It comes from the Rover SD1 version of the V8. You can check it by looking at amplifier pack on the side of the distributor, which should be marked "Lucas 9EM Ignition Module".
There was a slightly earlier version (1984) which had the coil strapped to a large aluminium box. The box contains mostly fresh air, and an older GM constant energy ignition amplifier.
Every 350i I've ever seen (and that's quite a few) has this on as the original system. This was also used on the Jaguar V12 which revs to 7000RPM.
Good news is that you cannot blow up a constant energy amplifier by putting an ordinary coil on it. It just can't get enough energy into it to make a good spark.
The system will reliably drive higher output coils, which I have used successfully on some older racers. One example of this is the American "Accel" coil. It is an ugly enormous yellow plastic thing, but it makes a spark like an arc welder!
No I have never seen an MSD on the dyno, so I have no idea whether it is valuable or not. I would be interested to have a look at one though, and I'll happily feed back the results.
I have set up twin turbo motors with the standard ignition system and they work just fine, as long as you use the right plugs and leads. No problem with burn time or energy, so I'm quite happy with it (which doesn't mean there aren't better ones of course).
Remember a similar distributor, coil, and constant energy amplifier are also successfully deployed on the Sierra Cosworth.
More recently I have been using the Omex mappable ignition system (highly rated!) on these type of installations, and you can even program the energy put into the coil.
Lumenition do three different systems, two of which are optically triggered from the distributor, and one is a mappable system. The two distributor systems use an optical pickup, although I have only found a fitting kit for the earlier Opus distributor. One is a normal system, and the other is also a constant energy system. I have set up and tested all of these systems.
In practice the standard constant energy system does not seem to pick up any interference, and I did monitor it very carefully with an oscilloscope. This is even true on forced induction motors under heavy load.
I hope this doesn't come across as heavy-handed or know-all - it isn't meant to!
>> Edited by Mark Adams on Sunday 8th September 00:39
Mark:
It's funny that you should mention using a 'scope, 'cos my 390 has always had a misfire/ stutter of some descrption that I've not yet got to the bottom of.
I hung a scope on the trigger pulses from the ignition amp as I was trying to spot an uneven pulse train, and there does seem to be a lot of spurious crap on there. However if you put a strobe on the HT, or fit those daft neons into the plug leads, the firing pulses seem to be pretty regular.
Which led me to look at the fuelling... so I put LEDs on each of the injectors to see if they were firing irregularly, but they seem OK too.
Ee, it's a laugh, isn't it... ;-)
Ian
It's funny that you should mention using a 'scope, 'cos my 390 has always had a misfire/ stutter of some descrption that I've not yet got to the bottom of.
I hung a scope on the trigger pulses from the ignition amp as I was trying to spot an uneven pulse train, and there does seem to be a lot of spurious crap on there. However if you put a strobe on the HT, or fit those daft neons into the plug leads, the firing pulses seem to be pretty regular.
Which led me to look at the fuelling... so I put LEDs on each of the injectors to see if they were firing irregularly, but they seem OK too.
Ee, it's a laugh, isn't it... ;-)
Ian
Still claim that it´s not a constant energy system. How could it be that whitout a "capacitor" storage build in(CDI)? (that will provide same energy over 10000rpm on a V8) The special CDI coil will then step up the voltage from the CDI output, like 250-500v, to 25000-50000v at the coil output.
But, i doesn´t matter in this case since Mark as an experienced bloke is telling us that it >normally< works fine in the rover v8 and that´s all we really need to know!
Ian, that´s my point. Guess what it lookes like with a MSD solution that gives multiple sparks during 20 crankshaft degrees.. Ok, what happens with the REV counter when the engine misfires/stutters ? Showing more/less RPM ?
But, i doesn´t matter in this case since Mark as an experienced bloke is telling us that it >normally< works fine in the rover v8 and that´s all we really need to know!
Ian, that´s my point. Guess what it lookes like with a MSD solution that gives multiple sparks during 20 crankshaft degrees.. Ok, what happens with the REV counter when the engine misfires/stutters ? Showing more/less RPM ?
Hi Guys, Have I opened a can of worms or what ?
The good news is two fold. I decided my yellow wire throu black conector (and then black wire) must go to ground. I think it has had a positive effect.
I replaced the sports coil with the original and replaced the codenser and hey presto no more missing !
Shame about my luxurious gold anodised coil though !
Thanks for the input.
Keith
P.S Mark, God your hard to get hold of !!
The good news is two fold. I decided my yellow wire throu black conector (and then black wire) must go to ground. I think it has had a positive effect.
I replaced the sports coil with the original and replaced the codenser and hey presto no more missing !
Shame about my luxurious gold anodised coil though !
Thanks for the input.
Keith
P.S Mark, God your hard to get hold of !!
Just to make things worse, the ignition amplifier is a bit fussy in terms of what you might hang of it and will often go into I'm not going to work mode. Found this when I tried fitting a psrk cut traction control unit. The amplifier didn't like it and refused to fire fo more than a few seconds. Had to go to a injection cut system instead.
Steve
Steve
The stutter is too brief to show up on the rev counter as such; you can see the engine rock slightly though and hear it in the exhaust note.
I did wonder whether my rev limiter (spark cut) may have been a cause but the stutter is still there with the limiter unplugged.
It's not a huge defect: just detracts from what otherwise sounds a very smooth engine.
Ian
I did wonder whether my rev limiter (spark cut) may have been a cause but the stutter is still there with the limiter unplugged.
It's not a huge defect: just detracts from what otherwise sounds a very smooth engine.
Ian
And some of the engines are soo smooth...
Well, the ECU is trigged by the + side on the coil. Any problems with the ECU input or signal quality would probably make the injection system react and cut down on the fuel, FAST. Still the ignition will work all the time!. And then we have the flapper pot and the trottle pot that could make the fuel system react fast.
Well, the ECU is trigged by the + side on the coil. Any problems with the ECU input or signal quality would probably make the injection system react and cut down on the fuel, FAST. Still the ignition will work all the time!. And then we have the flapper pot and the trottle pot that could make the fuel system react fast.
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