P38A Changing HT Leads

TallPaulB · Nov 29, 2018

Howdo all,

I'm looking at changing the plugs & leads on my 4.6 V8 for a set of magnecores. I've been advised that changing the leads is much easier if you take the inlet plenum off the top to give you more room to play with. However, that seems a lot of work. One mitigating factor is that I have LPG pipes running over the top of the engine making removal of the plenum more difficult, but also giving less room to manoeuvre if I leave the plenum where it is.

So...pros and cons? Would removing the plenum allow access to anything else I could tidy up / check / do random maintenance on? Is it likely to break anything / expose any other problems waiting to happen?

Grrrrrr · Nov 29, 2018

The dis-pack is right down the back of the engine. Absolute sod to get to. Suspect magnecores would be overkill but sure one of the v8 owners like @biketeacherdave or @ukadamwest running LPG could confirm. You might be able to get at it from underneath with an arm up the back but reckon it'd still be tight. @Saint.V8 probably knows a trick or two.

Best do the plugs while you're about it. As for what else, well, that way lies madness. You'll think of the valley gasket, then you think well, maybe the timing chain while I'm about it. Then the water-pump is nearby and the thermostat ... and the auxilliary belt ... oooo, and the oil pump too ...

biketeacherdave · Nov 29, 2018

Magnecores are over kill standard leads and plugs are good enuff. You can swop the leads out without taking anything off iv decent size hands and i managed it just do x1 lead at a time so you dont mix then up

Saint.V8 · Nov 29, 2018

Obvs easier with the plenum off, but as BTD says above - it is possible with it all in place, just a pain the backside.

Assuming GEMS, If you do take the plenum off, it is a simple case of:

Disconnect throttle pot
Disconnect IACV
Remove intake duct
Remove the split pins from throttle and CC cables
Remove pins from the above
Remove cables
Undo the Gearbox diptick tube from cable retainer - assuming pre-99
Remove EVAP Vacuum pipe
Undo the throttle body coolant pipes
undo the 6 socket cap bolts
Lift off

Reseal on refittment.

TallPaulB · Nov 30, 2018

Sorry, I should have said it's a Thor, a 2001 vintage.

My main concern is the LPG system. It's a dual vapouriser, so has two sets of pipes running over the top of the Plenum which a) reduce the amount of room I have to get my hands down the back of the engine but also b) make me more wary of taking the plenum off since I'll have to disconnect at least some of the pipework.

@biketeacherdave I've seen people say the magnecor leads don't make a difference, and I've seen people say they improve fuel economy and make choirs of angels sing when you drive past, but I've not seen anyone say they're any worse than the standard leads..... so happy to pay the extra even if they are overkill

biketeacherdave · Nov 30, 2018

You really will be wasting your money on magnacore leads but its up to you, I don't have LPG on my Thor but its going on over Xmas holidays

siddeley · Dec 1, 2018

Hi.. changed leads ( magnecore) with everything in situ...you will need a good torch and change one lead at a time.... all was good. (Thor engine)
regards

siddeley · Dec 1, 2018

Hi.. changed leads ( magnecore) with everything in situ...you will need a good torch and change one lead at a time.... all was good. (Thor engine)
regards

P38A Changing HT Leads

TallPaulB

Active Member

Grrrrrr

Technician, Bodgit & Scarper Ltd

biketeacherdave

Well-Known Member

Saint.V8

Dyed-in-the-wool 100% RR Junkie

TallPaulB

Active Member

biketeacherdave

Well-Known Member

siddeley

Member

siddeley

Member

Similar threads