Spark plug leads..

Got a problem with your FTO? ask about it here

Moderators: IMC, Club Staff

User avatar
payaya
Oldtimer
Posts: 3662
Joined: Sat Sep 06, 2003 5:00 pm

Post by payaya » Thu Sep 02, 2004 2:09 am

ah theres three spark plug leads coming off the front bank of spark plugs, they themselves dont have spark plugs leads, as its got a type of coil on ignition setup.

The coils again, have one single lead coming off them, each going to one of the rear spark plugs. So 6 plugs, 3 have the coil directly connect to them. As the rear plugs dont have the coil on ignition type setup, they just run off leads, connected to one of the three coils at the front.

MADFTO states that from the ignition module, to the front set of coils, with have nothing to do with the spark leads, or rear bank of spark plugs, should be changed. But there shouldnt have to.

My best guess is she is just getting the wires mixed up. He states that the wires come out to the left of engine. Which can only mean one thing, spark plug leads.

User avatar
MADFTO
Mechanic
Posts: 449
Joined: Tue Apr 08, 2003 5:00 pm

Post by MADFTO » Thu Sep 02, 2004 11:16 am

Well from my logic, there has to be six leads in a wasted spark system with coil packs being over one bank of plugs ( The front bank )

Three Leads are connected to the coil packs (One to each) to the rear bank of plugs. These leads will have to deal with high voltage but low current.

The most important thing about these leads is EMI suppression.

Then you have three leads that have to connect to the coil packs to the ignition module to provide the primary coils of coil packs with 12V current. The current will be higher across these leads than the ones going from the coil packs to the rear bank, the EMI won't be that high across these leads but they have to be able to hold a decent amount of current.

Now if you replace the leads going from the coil packs to the rear bank of plugs, you are doing so to prevent EMI rather than improve the spark (of course you might get a better spark with better leads but the more important thing is EMI supression)

However, you are only affecting the performance of the rear bank of plugs when you replace these leads.

If you replace the leads from the coil packs to the ignition module, you'll most likely get a cleaner current for the coil pack to induce a high voltage discharge. This will affect all six plugs.

Now this is all knowledge based on what I know, I might be totally missing out on something. That's why i've gone and asked people in the know about this, why only replace three leads? I don't know which set of three are to be replaced by the magnecor leads I'm getting, but pictures of other leads I've seen replace the leads from the coil pack to the rear bank plugs.

So the big question is, why not replace the set of leads going from the coil pack to the ignition module? As the system is more dependant on these leads than the leads between the two banks.

Am I making any sense? =)

ruchi
Oldtimer
Posts: 1845
Joined: Tue Oct 14, 2003 5:00 pm
Location: Melbourne

Post by ruchi » Thu Sep 02, 2004 11:34 am

You make perfect sense to me Eric, and I agree with you. I raised the concept of replacing these additional leads earlier in the thread but it only seemed to confuse people so I've been quiet since then. :D

To ensure even distribution across all the plugs and to lower both resistance and noise, I'd be replacing all the leads.

Now it's just a matter of working out the exact configuration of what is required.
MIVEC is My Friend :D

fto12345
Mechanic
Posts: 499
Joined: Thu Aug 28, 2003 5:00 pm
Location: Sydney

Post by fto12345 » Thu Sep 02, 2004 11:37 am

I'm sorry guys but doesn't MADFTO seem like he is contradicting him self?

So which wire are you saying are the ones that are replaceable?

Thanks,

User avatar
MADFTO
Mechanic
Posts: 449
Joined: Tue Apr 08, 2003 5:00 pm

Post by MADFTO » Thu Sep 02, 2004 1:45 pm

Technically both set are replacable. I've seen only pictures for sets that replace the leads from the coil packs to the rear plugs.

I'm just trying to find out why the leads from the coil pack to the ignition module aren't being replaced.

Oh, if you're doubting that they can be replaced, think of this. A lot of jap imports with inline 6 engines have a coil pack for each indiviual spark plug. Now all the leads are from the ignition module to each coil pack. (A non wasted spark system essentially) and you see modified engines with these leads (and more likely the whole ignition system) upgraded.

User avatar
payaya
Oldtimer
Posts: 3662
Joined: Sat Sep 06, 2003 5:00 pm

Post by payaya » Thu Sep 02, 2004 2:59 pm

the leads you say going to the coil packs are spark plug leads though, they are normal 16 gauge wire or something.

the falcons, to the coil have smaller gauge wire. Then it has a king lead, going to the dizzy, and 6 spark plug leads going to the spark plugs.

User avatar
MADFTO
Mechanic
Posts: 449
Joined: Tue Apr 08, 2003 5:00 pm

Post by MADFTO » Thu Sep 02, 2004 4:45 pm

Honestly I don't know what the composition of those leads would be, however I doubt it'd be standard solid core wire. Have to consider EMI and RFI =)

Sounds like falcon's use a dizzy with points with the coil feeding the dizzy. Coil probably is still controlled by an ignition module control the firing . . . *shrugs* I wouldn't know =)

User avatar
shiggz
Grease Monkey
Posts: 134
Joined: Thu Jul 09, 2015 1:26 am
Location: Perth, WA
Re: Spark plug leads..

Post by shiggz » Wed Jun 01, 2016 4:54 am

Bit of a massive revival.. But what was the conclusion to this?
Is it actually okay to just replace the 1 set of ignition leads from the coilpack to the rear bank, or should the other set from the coilpack to the ignition module be changed too?


(Also hey MadFTO, I haven't met you in person, but i'm in WA too, apparently you've met Rob.. i've also talked to RPW about your build as well haha)
Sututututuuuuu

Image

User avatar
Bennoz
National President
Posts: 23443
Joined: Fri Jan 21, 2005 6:00 pm
Location: Sydney
Contact:
Re: Spark plug leads..

Post by Bennoz » Wed Jun 01, 2016 9:42 am

There is only 1 set from packs to rear plugs.
Image

User avatar
MADFTO
Mechanic
Posts: 449
Joined: Tue Apr 08, 2003 5:00 pm
Spark plug leads..

Post by MADFTO » Sat Jun 11, 2016 5:01 am

Hi. Yeah this is a pretty old thread :) back before YouTube was around and a good 12 years ago. Jesus.

Anyways, in this case, we were talking about replacing the High tension (HT) wires that leads from the coil packs to the rear bank spark plugs.

The "ignition module" is the ECU and it's really just a signal wire.

We can't replace this as it's part of a 3 pin plug that also has the 12V source and ground.
No real need to replace it either, the magic happens on the secondary side (the high voltage side) of the coil. You don't want the generated energy on this side to arc anywhere but across your plug gap. Lower resistance wires = more energy in the spark.

Plenty of stuff on the web these days to learn about ignition systems, not like before when we were fumbling around :)

Wiring diagram on page 4-21 in the electrical workshop manual if you care to know how it's all wired up.

Heh, I've kept pretty quiet since moving to WA.
Engine's back together now, should be getting some break in time on the dyno next week.


Sent from my iPhone using Tapatalk


Post Reply