What spark plugs to use??

G

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hey guys

just a quick one... i have been noticing sometimes during moderate accelration that it can drop revs... not by much but its noticable and couple of weeks ive been running seemingly a little rich...

Im thinking a spark plug change to start with and maybe run some injector fluid through it will a. help with the clicking we all love and b. provide smooth acceleration...

Am I right in thinking that?? or... have i fluffed it...?

:)
 

godzilla

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1/19 2002 FL Legnum Type 'S' Manual in Black with Suede Recaro's!
They all run rich the damn things
But as far as spark plugs are concerned, from what i know, a failing plug(s) will cause a miss rather then revs dropping under load?
If your after plugs there are a couple you can use but the most popular is the NGK BKR7EIX but you can also use a 6.
 

Buckas

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yeh spark plugs will cause a miss, my alfa a couple of months ago was suffering from alfaitus and destroying a spark plug every 50 kms, kept some spares in the boot and swapped them when it died until i got timing and carbie settings adjusted. in the mean time it just bellowed lots of black smoke and was the most juddery car to drive, and struggled to pull me up a hill, let alone flat road
 
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yeah i may have just been sally sensitive about the acceleration... keep and eye on it... oh yeah NGK cool... from what ive read... is it a bit of bi*ch to swap the rears?
 

SiliconAngel

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Its not that bad, but yes its a lot more involved than most cars. You need to remove the engine cover, intake Y pipe and intake manifold, but its still only a half hour to 45min job :) I recommend doing your plug leads while you're there, too.
 

Buckas

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is there any way to tell if the leads really need replacing? ive got a set of plugs on the way and would do it at the same time but ive bought a few other things in the few weeks ive owned the car and its starting to add up...can i test/check them at all while im under there and what do i look for?
cheers for any help
 
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Section 16, page 13 of the Japanese workshop manual has the details for checking both the leads and the coil packs. Max resistance is 14 kilohms for the leads.
 

Buckas

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hmm resistance. anyone know any 'backyard' methods?
 

SiliconAngel

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'99 Legnum VR4 Black MT
Remember your coil packs produce huge voltage, although at very low amps. While getting in the way won't kill you, it could leave you with a very nasty burn. If you don't know what you're doing I wouldn't be fooling around with leads.

Besides the most common problem with leads is breakdown of the insulation causing shorting - the lead will test fine as long as its not shorting out at that particular moment (which is often the case when you're trying to test something, of course ;)).

Considering you'll be putting 100,000km plugs in you're highly unlikely to be pulling your manifold off to replace the leads if you don't do them now, but they're a serviceable component that's MEANT to be replaced periodically. I understand what its like to start running low on cash, but honestly just how much will you really miss $100? It may well save you headaches down the track, not to mention fuel economy. On the other hand, the ones that are in there may be 100% ok, but that's the thing with second-hand cars - unless you've replaced it yourself, you just don't know.
 

Buckas

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oh the sensible answer i thought but didnt wanna hear, i guess i did all plugs and leads etc when i bought my alfa (dad was paying though:)) and the leggy deserves the same. i suppose the exhaust will have to wait a bit longer then :(
 
G

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To check resistance of the leads get yourself a $10 multimeter. Procedure is that you unplug them from the coil pack and from the plug and totally remove from car to test. Set the dial on your multimeter to the correct range, jam a probe in each end on the lead and read what it says. If you don't have a multimeter you can pick up awesome ones dirt cheap these days and they always come in handy, even if it's for only checking continuity (to see if a wire is broken or not).

But as Trevor says, leads are disposable after a certain amount of time. They put up with a lot of heat over the years so it never hurts to replace them if you have the cash. I'm not exactly sure what the service interval is for them, but I'd feel comfortable with something like 60,000kms. Of course, if you are putting those 100,000kms iridium plugs in with new leads, then just leave them until you do the plugs next time too. But personally I will be replacing my iridium plugs well before the 100,000kms anyway.

The other common way leads die is by yanking them out by the lead and not by the boot as you are supposed to do. Mass produced leads usually have a pretty crappy way of connecting the lead to the boot, IIRC the boots usually have what looks like a self tapping screw sticking out and the this screws into the lead an hopefully makes good contact with the wire core. In practice.. well, who knows! But the ICE leads are made differently and the wire goes all the way in and down through the boot and is secured directly to the connector inside that clips onto the spark plug.

Be sure to use nickel anti-seize on your spark plug thread and read the box for tightening instructions. Also put a healthy amount of dielectric grease on your plug ceramic insulator and metal top connector. This will stop the things from getting stuck and you will really thank yourself when it comes time to remove them. Both of these products can be picked up from a good auto parts store, I think Permatex make them in little tubes or sachets. Repco & Bursons should have them, but all the Super Cheaps around me don't stock them.

Edit: Oh yeah, Trev, Fuel economy! Will probably pay for themselves in the first month!
 

Buckas

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the issue is fixed, pay day today! ill get onto ice after my exam and order them in this morning.
thanks for the help guys
 

Buckas

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just called michael at ice, very easy to deal with and leads are due interstate 2 days at the latest. thanks to everyone who set that up
 
G

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I was gonna ask if you wanted to order two and save on shipping, but it looks like it's too late :) That's ok
 
G

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hey guys

just quickly. The NGK 6's and 7's.. are 7's used in cars with a higher boost level or would they be fine in stock setting... I only ask because im upping boost when I get my exhaust made and dont want to have to change from 6's to 7's in a short time frame...??

:)
 

godzilla

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1/19 2002 FL Legnum Type 'S' Manual in Black with Suede Recaro's!
If you are going to be running a heap more boost i.e. 14-15psi then go the 7's but even moderate boost increases should be no worries for the 6's.
 
G

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i was thinking of 12psi tops... the 6's should cope with that trev?
 

godzilla

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1/19 2002 FL Legnum Type 'S' Manual in Black with Suede Recaro's!
AFAIK they will cope fine. I am running just under 12 now and my 6's haven't missed a beat!!
 
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