spark plug leads
Discussion
I had some nice red 10mm race leads, and they never missed a beat in the last couple of years, unlike the 2 set of 8mm Mag***** that lasted 6 months each
In fact after the fire you could still make out all 8 10mm leads and not the poxy 8mm coil to dissy lead
Got some normal ford leads for the coil packs that will go back on
In fact after the fire you could still make out all 8 10mm leads and not the poxy 8mm coil to dissy lead
Got some normal ford leads for the coil packs that will go back on
Thinking inside the box, give or take a few volts, just my two pennyworth really.
When these engines left the showroom with a their bog-standard inductive ignition system the normal HT voltage would be in the range 10 - 20000 volts and the fitted (commonly black) plug leads would be perfect for that.
Those same leads also (mostly) had an internal resistance that aided the interferance supression needed for on-board entertainment and in-range TV/radio requirements.
Upgraded ignition system such as CDI (capacitive discharge) have the capability to generate 30 - 45000 volts for which the original leads were not designed. So upgraded HT leads would be required obviously needing better insulation, perhaps making them thicker, using in-vogue easily torn Silicone, optionally with or without internal resistance and of course - seductive colours to encourage illicit thoughts of under-bonnet sex.
A phenominally successful marketing trick of the spark plug lead supplier is to persuade owners of bog standard inductive ignition systems that they crave a change in plug lead. The advertising hype may even claim fatter sparks and more power, even though other components are unchanged.
The probable truth of the matter however is rooted in the original inductive ignition system design. If the voltage is the same and the spark plugs are original spec then as long as the HT leads are undamaged, clean and correctly spaced, then a doubtful upgrade serves only three purposes:
o possible degrading of the ignition system and interferance suppression by fitting incompatible leads
o falsely leading the owner into a feel-good state of mind
o swelling the coffers of plug leads suppliers by increasing turnover
The true benefits to the engine being approximately nil or maybe even negative.
On the other hand, if an ignition system has been upgraded to (say) CDI where engine speed and performance is being improved by other means, fast road cam, porting, exhaust systems, injection systems, what have you, then the acquisition of upgraded ignition leads to handle more, hotter and faster sparks is de rigueur. They would however have to be technically matched to the new system requirements, not bought randomly for the best colour match.
In the meantime unless some changes have been made requiring a voltage and spark performance beyond bog standard inductive ignition systems, the best results will be had from a scrupulously clean ignition system, correctly timed, correctly gapped and using originally specified undamaged components.
When these engines left the showroom with a their bog-standard inductive ignition system the normal HT voltage would be in the range 10 - 20000 volts and the fitted (commonly black) plug leads would be perfect for that.
Those same leads also (mostly) had an internal resistance that aided the interferance supression needed for on-board entertainment and in-range TV/radio requirements.
Upgraded ignition system such as CDI (capacitive discharge) have the capability to generate 30 - 45000 volts for which the original leads were not designed. So upgraded HT leads would be required obviously needing better insulation, perhaps making them thicker, using in-vogue easily torn Silicone, optionally with or without internal resistance and of course - seductive colours to encourage illicit thoughts of under-bonnet sex.
A phenominally successful marketing trick of the spark plug lead supplier is to persuade owners of bog standard inductive ignition systems that they crave a change in plug lead. The advertising hype may even claim fatter sparks and more power, even though other components are unchanged.
The probable truth of the matter however is rooted in the original inductive ignition system design. If the voltage is the same and the spark plugs are original spec then as long as the HT leads are undamaged, clean and correctly spaced, then a doubtful upgrade serves only three purposes:
o possible degrading of the ignition system and interferance suppression by fitting incompatible leads
o falsely leading the owner into a feel-good state of mind
o swelling the coffers of plug leads suppliers by increasing turnover
The true benefits to the engine being approximately nil or maybe even negative.
On the other hand, if an ignition system has been upgraded to (say) CDI where engine speed and performance is being improved by other means, fast road cam, porting, exhaust systems, injection systems, what have you, then the acquisition of upgraded ignition leads to handle more, hotter and faster sparks is de rigueur. They would however have to be technically matched to the new system requirements, not bought randomly for the best colour match.
In the meantime unless some changes have been made requiring a voltage and spark performance beyond bog standard inductive ignition systems, the best results will be had from a scrupulously clean ignition system, correctly timed, correctly gapped and using originally specified undamaged components.
Pilo-Wedgebits said:
Red leads ordered ..... does that mean shes nearly there ? 
need to bleed brakes, fit exhaust, fit leads and bolt the body down, but once leads come i am planning to see if it will start, so may be next weekend, hope to be ready for mot by the time i go to lemans.Thanks for your comments lads.
The reason i was asking is that i have 2 cylinders not working properly [the car run's ok, but stutter's after a good run].
It started when a friend found that one of the injector wire's was cut so started to fix it then found out that the owner before me had looped wires from cylinder 1 to 3 together, which fire at the same time.Think that's because of a problem in the ecu.
Checked the plugs last night and found all plugs had a light deposit on them except for 1 and 3 cylinders plugs which were clean as a bell.
Also checked fuel pressure [38psi] then cylinder test [150psi] renewed plugs and changed some leads, there's also a new ballast coil just fitted.
Any suggestions would be gratefull.
Thanks john.
The reason i was asking is that i have 2 cylinders not working properly [the car run's ok, but stutter's after a good run].
It started when a friend found that one of the injector wire's was cut so started to fix it then found out that the owner before me had looped wires from cylinder 1 to 3 together, which fire at the same time.Think that's because of a problem in the ecu.
Checked the plugs last night and found all plugs had a light deposit on them except for 1 and 3 cylinders plugs which were clean as a bell.
Also checked fuel pressure [38psi] then cylinder test [150psi] renewed plugs and changed some leads, there's also a new ballast coil just fitted.
Any suggestions would be gratefull.
Thanks john.
Jonny weggie said:
2 cylinders not working properly ... car run's ok, but stutter's after a good run ... found out that the owner before me had looped wires from cylinder 1 to 3 together
depending which side of the injector, that almost certainly compromises the injector function which should each have their own resistor inside the resistor pack, instead of sharing one with an adjacent injector. Oops! Jonny weggie said:
found all plugs had a light deposit on them except for 1 and 3 cylinders plugs which were clean as a bell.
Because injectors 1 and 3 only get half their operating current, causing partial function, delivering less fuel, resulting in little bangs and no meaningful deposits on the spark plugs.The illusion is that its running OK.
Again
Jonny weggie said:
found all plugs had a light deposit on them except for 1 and 3 cylinders plugs which were clean as a bell.
There is another scary explanation - Cylinders 1 and 3 could share a cracked coolant gallery, and water is getting into the combustion chambers, effectively steam cleaning the innards thereabouts - but you dont wanna go there, right? 
We did a pressure test on the cooling system at 15psi and found that there was a leak from the expansion cap, so we discounted the possibilty off water going esle were. PS- it was a new cap bought at one of the wedge show's.
So is the solution maybe to get the ecu fixed and put the injector wires back the way they should.
cheers jonny.
So is the solution maybe to get the ecu fixed and put the injector wires back the way they should.
cheers jonny.
Because you only "think" its a problem with the ECU, one step at a time would be prudent.
Put the wiring back as it was. Now run the car, and check if the problem is gone or changed in any way.
To be quite honest as the ECU switches to ground all the injectors on one bank at the same time, it is illogical for the grounding not to work on all four injectors.
It could however, be a problem with the ECU multiplug connector or a soldered joint inside, where that particular wire is grounded by the power transistors there-in.
More likely, I think, any fault may be in the wiring to, or the function of, the Power Resistor Pack, whose connector is a dodgy item and the resistors vulnerable to overheating or corrosion damage. The Injectors and the Resistor Pack work together to meet the injection needs.
To see exactly how that part of the system works go here and open the PDF from that page.
If the fault is not resolved with the above investigation and suspicion now falls on the ECU, then testing by substitution is the preferred option before shelling out moolah.
Be aware that over 80% of all Flapper Efi faults are due to wiring/connector issues and/or air leaks into the plenum chamber.
In your case the main suspicion will be with local wiring to the components involved.
On the same archive are all the other components and systems of the normal 3.5 Flapper Efi system should you need further reading. In particular all the components, except the ECU can be tested using simple equipment and following the instructions in each section.
Put the wiring back as it was. Now run the car, and check if the problem is gone or changed in any way.
To be quite honest as the ECU switches to ground all the injectors on one bank at the same time, it is illogical for the grounding not to work on all four injectors.
It could however, be a problem with the ECU multiplug connector or a soldered joint inside, where that particular wire is grounded by the power transistors there-in.
More likely, I think, any fault may be in the wiring to, or the function of, the Power Resistor Pack, whose connector is a dodgy item and the resistors vulnerable to overheating or corrosion damage. The Injectors and the Resistor Pack work together to meet the injection needs.
To see exactly how that part of the system works go here and open the PDF from that page.
If the fault is not resolved with the above investigation and suspicion now falls on the ECU, then testing by substitution is the preferred option before shelling out moolah.
Be aware that over 80% of all Flapper Efi faults are due to wiring/connector issues and/or air leaks into the plenum chamber.
In your case the main suspicion will be with local wiring to the components involved.
On the same archive are all the other components and systems of the normal 3.5 Flapper Efi system should you need further reading. In particular all the components, except the ECU can be tested using simple equipment and following the instructions in each section.
Thanks for the info H/J/2,to cut a long story short it ended up being a wire needing changed around in the injector system, because 1 and 3 cylinder plugs were clean meant that we were actually running on 6 cylinders [pulled out inj and were no difference what so ever] which meant that we travelled to chatsworth [450miles away] on 6 cylinders.
Problem now sorted, thank again.
john.
Problem now sorted, thank again.
john.
Jonny weggie said:
We did a pressure test on the cooling system at 15psi and found that there was a leak from the expansion cap, so we discounted the possibilty off water going esle were. PS- it was a new cap bought at one of the wedge show's.
Not one of mine was it? Do however note that they are rated at 15psi, so they will lift at that pressure and let water out into the expansion bottle. I spose it depends how accurate your pressure gauge is. If there's a problem with it I'll swap you one at the next wedgefest and get it tested. Jonny weggie said:
which meant that we travelled to chatsworth 450miles away on 6 cylinders.
Thinks! One would surely have noticed, with two pots on the same side not providing energy, the vibration would be worrying! And, you did say that some wires were joined, as if to cover for a prior problem, making it possible that the engine WAS running on 8, but with two of them under par. Whatever, good news its sorted.Edited by honestjohntoo on Monday 17th May 13:25
H/J/2,
Driving up to 60mph was fine but after that it coughed and spluttered [not violent or anything like that] so did know there was something wrong just did'nt know what, even on tick over it was still at 900rpm [smooth]. I've heard that these engines are fairly roburst and forgiving, the rover 350i.
john.
Driving up to 60mph was fine but after that it coughed and spluttered [not violent or anything like that] so did know there was something wrong just did'nt know what, even on tick over it was still at 900rpm [smooth]. I've heard that these engines are fairly roburst and forgiving, the rover 350i.
john.
Fine words from Honest John indeed. I'm planning to upgrade my ignition system, possible to an MSD.
I have these 10.4mm leads on both of my V8's:
http://www.summitracing.com/search/brand/Taylor-Ca...
Half the cost of Ripoff Britain including postage and nearly twice as fat.
I like fat leads and all the hype - makes me think my cars faster that it really is
Phil
420 SEAC
I have these 10.4mm leads on both of my V8's:
http://www.summitracing.com/search/brand/Taylor-Ca...
Half the cost of Ripoff Britain including postage and nearly twice as fat.
I like fat leads and all the hype - makes me think my cars faster that it really is
Phil
420 SEAC
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