Going to be changing my spark plugs when they come in the mail (Ngk irid ix's) as they need to be changed. The car has also been behaving a little strangely for the last few months (When cold, will bog down sometimes when I put my foot down, then suddenly full power and will surge forward). This doesnt happen all the time though. I changed the fuel filter very recently (And did a full service) so don't think its a fuel issue.
Im fairly sure the rear plat spark plugs have been in the car for 125,000k's, so they def need to be changed. I have no idea about the fronts, but i'm replacing all 6 with irids just to be safe. I'm guessing this is what is causing the 'bogging down'.

My question is, is it worth changing the ignition leads too? Could they be part of the problem? Ive read that the bosch leads are only like $50 from supercheap auto?
Are they hard to change? I'm guessing not?

Edit: Just thought id elaborate a little on the problem, to make it a little easier to diagnose. When I put my foot down (Almost always when the engine is cold), it just takes like 2 seconds to accelerate, going up very slowly, then it feels like something 'lets go' then it revs up quickly. It only does this while cold, and its only every now and then.
Ive also noticed a little lack of power anyway in the low rev range (Up to around 3k, then its all good). Thats why I was thinking maybe it was plugs/leads?

Im pretty sure its not the injectors, as the car gets revved high quite often so I think they should be fairly clean....

$50? Try $120 <_<

And no they aren't hard, they'll add 15-20 seconds extra to the replacement of each plug.

I couldn't imagine a bogging down issue could ever be due to leads, as it would take multiple cylinders struggling to cause the symptoms you've presented. If it were on the ignition side of things it would be rotor, rotor cap or the more likely suspect, the coil.

Failing fuel pump maybe? Sensor issue? List goes on

$50? Try $120 <_<

And no they aren't hard, they'll add 15-20 seconds extra to the replacement of each plug.

I couldn't imagine a bogging down issue could ever be due to leads, as it would take multiple cylinders struggling to cause the symptoms you've presented. If it were on the ignition side of things it would be rotor, rotor cap or the more likely suspect, the coil.

Failing fuel pump maybe? Sensor issue? List goes on

Oooo $120! So do you think its worth it anyway? Ive had the car for like 4 years, pretty sure they havent been changed while ive had it....how often do they need to be changed?

If your changing leads then get some topgun leads instead
Also check the condition of the dizzy and rotor button I think it is?

If your changing leads then get some topgun leads instead
Also check the condition of the dizzy and rotor button I think it is?

Really?? Ive read a few threads on here about leads and they all said to stay away from top gun! ??? It seems they fail very quickly... :/
How would I go about checking the 'condition' of the dizzy and rotor button??

Open the dizzy (where the spark leads all meet in case you didn't know), and check that the contacts on the cap you take off aren't work, they're basically metal knobs that the rotor touches to send a spark to the plugs, and check the metal contact on the end of the rotor for wear too. This is very unlikely to be your issue however as they would show general problems with the car, not just in bursts while cold.

I still blame the coil or a sensor.

Open the dizzy (where the spark leads all meet in case you didn't know), and check that the contacts on the cap you take off aren't work, they're basically metal knobs that the rotor touches to send a spark to the plugs, and check the metal contact on the end of the rotor for wear too. This is very unlikely to be your issue however as they would show general problems with the car, not just in bursts while cold.

I still blame the coil or a sensor.

Ahh ok, thanks woob, i'll give that a shot on the weekend!
Would the coil be intermittent like this? And can I test the coil to see if its working properly?

Also, when you say sensor, do you mean oxygen sensor?

what does it idle like? rough? When was the last time you change the Oxy Sensor?

For what it is worth, I had TopGun leadson my Pajero and they caused masssive backfires. I opened the bonnet at night and you could see the inside track of every lead by the internal arcing and there was arcing externally to the engine. Then, to top it off, the plug insulators had all melted and fused to the spark plug bodies. This was after 10000 km. NOT IMPRESSED! I now use NGK or Bosch leads on both the Magna and the Pajero.

Plug leads - don't change them unless they are faulty, use a multimeter to measure the resistance of each lead, the manual will tell you what the resistance should be. Why waste $120 replacing some bits that aren't actually known to be faulty? Anyhow, "bogging down" is nothing like a misfire, which would point to an ignition problem - I'd be checking the intake system for air leaks first.

But the bogging down is only intermittent, air leaks again would be constant. Fuel pump is the other one that may be on it's way out

So I changed the spark plugs today! Rear plugs turned out to be irids, not plats as I thought they were. So its possible that the irids have been in these for like 125k k's! I also noticed that the irids that were in there were a different heat setting (5, instead of the 6 that my new ones are...) It was def the 6's that I needed though....Also noticed that the old plug tips had a white powder colour to them, the rear ones were particularly bad. ?
Also noticed that the front spark plugs had a little bit of oil on them, which im pretty sure means that the tube seals need doing. The annoying part is that I had the tube seals done with my timing belt service like 20,000k's ago..... also had the rocker cover gasket done (Which wasnt done correctly and has been leaking ever since...). I just wish mechanics would do a decent job when im paying good money (Paid like $1200+ for that service, and they didnt even change the spark plugs).....

Car feels a bit smoother now, and I would even say it feels like it has slightly more power! Could be a placebo though..

Only did spark plugs today, wanted to make sure it wasnt the spark plugs before I started checking other things! The leads all looked fine though, no cracks or anything. Might still test them on the weekend..

White powder means the cylinders are running lean, black/grey is pretty normal, black and oily I'm not sure if it could be one of a fee things or not

Might be a long shot, but when was the last time the throttle body got cleaned?
Reason I ask, I had some hesitation during acceleration when cold also, but had planned on cleaning it.
It was full of gunk when I took the intake off the throttle body, I manually moved the flap and felt some sticking, took it off, gave a thourough clean, put on stated car and hey presto, no more hesitation.

White powder means the cylinders are running lean, black/grey is pretty normal, black and oily I'm not sure if it could be one of a fee things or not

So tis running lean? Hmmmm....... wonder why that is... :\
Should I be worried?


Might be a long shot, but when was the last time the throttle body got cleaned?
Reason I ask, I had some hesitation during acceleration when cold also, but had planned on cleaning it.
It was full of gunk when I took the intake off the throttle body, I manually moved the flap and felt some sticking, took it off, gave a thourough clean, put on stated car and hey presto, no more hesitation.

I have no idea lol. I did give it a quick clean today, just stuck a rag in there to try and wipe some of the crap off. (Black stuff came off the butterfly, I gave the throttle cable a few pulls but it seemed to be working so I didnt give any thought to it... I probably would have given it a better clean if I had know it could be part of the problem :( Maybe Ill give it a clean on the weekend! How do you suggest I clean it? (Degreaser or something?)

Throttlebody/carby cleaner

Throttlebody/carby cleaner

Ahh, that makes sense! Hahaha