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The only place for a coil spring is up Zebedee's arse.
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Joined: Dec 30 2015
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I've only once gapped the BPR6ES plugs down and it seemed to make no difference whatsoever so I've just left them as they are. If the ignition system is designed for plugs with a 1.1mm gap (as the original recommended Champions had), it shouldn't do any harm at all. I ran a set of the Iridium BPR6EiX for around 40,000 miles up until the engine came out to go to V8 Dev. I didn't have any to put back in and my local factor has to order them in for me but keeps the nickel ones on the shelf, so at £1.99 each, I've been using them ever since. At least with changing them every 10,000 miles, there's less chance of them seizing in.

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Joined: Dec 30 2015
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I've always gapped them down to give the coil/coils an easier time with LPG. I guess it depends on how much zip the system has spare.

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Joined: Dec 30 2015
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She's been running fine on short trips since the Spark Plug debacle, but heading up the A19 tonight she started misfiring and feeling very rough.
My first thought was "Oh God, I've killed the cylinder with swarf from cutting the thread".
I couldn't get the Nanocom to connect either so I was filled with woe for another hour and a half until I decide to pull over again and give the Nano another go. This time it hooked up (I think I'd chosen the wrong vehicle or something) and showed me loads of multicylinder misfires, adaptation errors, and more interestingly misfires on pot 4.
The one I F"£$%D up was pot 6 on the other head (and the spark plug is still hanging in there) so I'm hoping this is unrelated.

Is it fair to assume that the first thing to do with a single cylinder misfire is to check the plug/wire for that pot? I think it's time to get the correct 14mm plugs and swap the rest over. My working theory is that cylinder 4 was misfiring enough to affect the reading from the O2 sensor which leaned out the rest of the engine. I'm hoping it's just an ancient old plug and not my cack-handedness that has trashed the whole engine :(

FWIW, idles sounds OK. Light throttle also OK so I cruise can at 70 on the flat but as soon as we start going uphill you can feel the engine "hunting" slightly and a lack of power.

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Joined: Jan 16 2017
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When I originally got the Disco (brought as spares or repairs off ebay without viewing first) it did have misfiring as the reason for sale. The previous owner had tried replacing the spark plugs and come to the conclusion it probabbly wanted a set of spark plug leads and I suspect felt out of his depth. I drove it back from the outskirts of Gloucester to Milton Keynes and it was fine as long as you didn't give it too much throttle though clearly something was wrong very much like what you describe. That turned out to be mostly his half-assed attempt at changing the plugs as 3 of them were so loose you could move them with your fingers, I replaced the leads at the same time as I didn't like the look of them at the same time, though suspect very little was actually wrong with them then.

If you suspect 1 lead is going bad, your best to change the lot. 1 cylinder logging misfires would suggest its more likely the plug or lead than the coil pack etc - these usually fail on a pair of cylinders, if you look at the diagram the top pair of the coil is one pair, the bottom two is another pair and so on. So if you had 2 on the same side of a single coil pack, it would suggest the coil is at fault (I'd suspect a damaged plug or shorted lead might cause the same result though as it would short circuit the good plug on that one).

Also changing the rest of the plugs given you know they are ancient would be a good plan, Might also be worth resetting the adaptives and seeing what your then left with, given the other logged errors. Once you've done that, have a look what the trims look like with the Nano would be the next step just in case something else is wrong (vacuum leak for example might explain some of the symptoms, particually if its not constant - something like a pipe rubbing against something so its only leaking some of the time)

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Joined: Dec 30 2015
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Thanks! I needed some validation before I pushed the PayPal button again....
I think this is going to the garage, it's too dark, cold and wet outside to be arseing around with a headtorch. They can take the risk on the 6 remaining oversize plugs too!

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Joined: Jan 16 2017
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Best hope Simon doesn't see you say that, he will be calling you a Nesh

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Joined: Dec 30 2015
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Anyone can be uncomfortable! :)

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Joined: Jan 05 2016
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To be fair... I'm probably going to get a garage to look at the clanging noise that I'm pretty sure is coming from the drive shaft on my BMW, because its dark and cold in the evenings, and I hate lifting up "normal" cars at the best of times. Let alone dropping the exhaust, heat shields and prop shaft out...

Sometimes its less faff to make it someone else's problem! :)

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Joined: Nov 16 2016
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Hehe that's true Bri!

Morat wrote:

Anyone can be uncomfortable! :)

Nesh bugger Miles! ;-) I prefer to work outside on cars and do so whatever the weather. There has to be a foot of snow before I think about working inside, when it's dark (nearly half my hours at work these days) I use work lights, I'd use work lights inside anyway. Boots, longjohns, thermal shirt, shirt, coat and Russian looking head warmer on today (not jumper weather yet lol) and I've been sweating. The birds/doves in the yard are so used to me being there they'll sometimes come and land on the ledge of an open car bonnet while I'm working on the engine hehe.

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work lights would be handy, no doubt! tbh, I'm at the age now when I want them during the summer too!