team_wingnut Posted March 17, 2012 Share Posted March 17, 2012 number 4 and number 6 missfiring, change plugs, no different change leads, no different, change leads on coil packs for their parner to try and move problem, no different, now the interesting bit... with ht lead on the plug, it missfires, when you hold it just over the end of the plug, (not on the plug) so you get the spark to jump, its runs with no missfire, second you put the lead on the plug in its 'normal' position, no spark! somebody try and help me out here, next thing to try is a box of matches and a gallon of diesel! Have spoken to nige today about it, and he's stumped completly! I could understand it if by doing the above the missfire moved, as in it would pinpoint a dodgy plug, or a dodgy lead etc, but this doesnt make sence! Dave Quote Link to comment Share on other sites More sharing options...
zardos Posted March 17, 2012 Share Posted March 17, 2012 You've checked the gap on the spark plugs, even new ones can be incorrectly gapped. Or try increasing the gap over standard. Quote Link to comment Share on other sites More sharing options...
simonr Posted March 17, 2012 Share Posted March 17, 2012 Are 4 & 6 on the same coil pack? I wonder if it could be the ballast resistors? Spark plugs / leads have a resistor in series - called a Ballast Resistor. The resistor can be in the plug or in the lead (high resistance wire). Sometimes the resistors break down or it may be that it is the wrong combination of plug & lead. It's possible that the resistor is in the coil pack. It could even just be that the environment in those two cylinders (pressure) make them more susceptible. The solution may be as simple of adding ballast plugs or leads on those, and possibly all of them. Si Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 17, 2012 Share Posted March 17, 2012 Could be a couple of dodgy injectors/connections if it's cylinder-specific. 4 & 6 aren't (or shouldn't be) on the same coil. Given there are 8 injectors wired to 4 pins on the main connector, could it be 4&6 are wired to one particular pin/wire and that one is dodgy? Edit: As with any MS issue, posting up a datalog (either file or screenshot) is helpful. Quote Link to comment Share on other sites More sharing options...
team_wingnut Posted March 17, 2012 Author Share Posted March 17, 2012 but why would the injectors suddenly work when I hover the ht lead over the end of the plug? plug gaps are fine, I havent checked them, but have swapped plugs around in the engine, as I have with leads, and the miss is still there! Quote Link to comment Share on other sites More sharing options...
Quagmire Posted March 17, 2012 Share Posted March 17, 2012 Have you tried swapping in a known good coilpack? I have had 3 fail on me and they have all done weird things right before they packup entirely. -Don't read this post as my bashing EDIS coilpacks - i'm not. I do a lot of mileage and as all have been second hand units they could have been to the moon and back before I got my hands on them... Quote Link to comment Share on other sites More sharing options...
team_wingnut Posted March 17, 2012 Author Share Posted March 17, 2012 No I havnt, worth a try, but I have swapped the coil packs over and it still doing it! Quote Link to comment Share on other sites More sharing options...
mad_pete Posted March 17, 2012 Share Posted March 17, 2012 So increasing the air gap increases the resistance for that spark path, so ballest resistor mentioned would make sense. Or some sort of interferance from that plug on the trigger wheel pick up ? Quote Link to comment Share on other sites More sharing options...
mad_pete Posted March 17, 2012 Share Posted March 17, 2012 and the coil packs are wired correctly ? (on both sides) and there is no spark bleed from say a tacho patch in ? Quote Link to comment Share on other sites More sharing options...
team_wingnut Posted March 17, 2012 Author Share Posted March 17, 2012 and the coil packs are wired correctly ? (on both sides) and there is no spark bleed from say a tacho patch in ? yes, checked, and double checked Quote Link to comment Share on other sites More sharing options...
landroversforever Posted March 18, 2012 Share Posted March 18, 2012 somebody try and help me out here, next thing to try is a box of matches and a gallon of diesel! I knew it... the solution to all petrol problems is always diesel Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted March 18, 2012 Share Posted March 18, 2012 This is defo an odd one ! The situation is as such that unless Dave holds the plug lead away from the plug there is a miss fire. Its the same with Known Good Plugs swapped, Plug Leads swapped, Coil Towers swapped ,and injector plugs swapped. However, having thought about this most of last night there is something I am thinking, but am unsure of WHY it would be the case, again I have an idea, but can someone actually comment on if there is something in what I am saying - or is it a nicely crafted straw I am clutching ? The thought is this When a plug lead is connected properly to a coil turret and a plug etc the spark is a predefided amount, and I right in thinking that if you pull the lead off and hold away from the plug, that the resulting spark is a vast amount more powerfull as it has to build up more to discharge and then travel across the gap ? If so then I am wondering if the injector is dribbling / squirting / vs a nice spray and as such the "Standard" spark is just not big enough to ignite the por fuel pattern vs a big F O spark that is, but only whilst plug lead held away from plug to force a monster discharge ? Thoughts ? ^^ ?? 2nd thought is poor connection to the Injectors. On pin 30 - brown and Ornage you will have 1 x wire to pin 30, but x 8 connected together as these are all powered at the ame time, thus any poor connection could leave the injector without a clean current - so recheck all the joins. Similarly, your problem is on ONE BANK and numbers 4 & 6, these are Slate & Red again these have multiple joins and all 8 wires should end up being joinly joined to pins 432 and 33 of the ecu - please recheck these multiple joins Other than the above will be interested to hear the "Plug spark jump voltage " views as to if I am talking complete and unfounded bowlux ? Nige Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 18, 2012 Share Posted March 18, 2012 Nige, I think you're thinking the same sort of thing as me but with different physics behind it TBH I haven't really worked out what effect the air gap has, my reasoning was only that just because fiddling with the spark makes it work, it doesn't mean the spark is the problem - and there's only really one other variable in the mix. Quote Link to comment Share on other sites More sharing options...
team_wingnut Posted March 18, 2012 Author Share Posted March 18, 2012 Morning Nige, Option one sounds plausable for the following reasons, when I whipped the plugs out of that bank, the two that were firing were clean, like new and a little bit moist with clean smelling fuel, the two that were missing were dry and as black as your hat, so could indicate that no or little or poor fuel supply. Spoke to old man about it last night, he said brand new saab 900's used to do it, they used to be delivered by trade platers and they used to have to pull the ht leads off and rest them on the top of the plug to drive them, he said the cure was new leads and plugs, but they never got to the bottom of it really! Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted March 18, 2012 Share Posted March 18, 2012 Want me to send you one of my nice DIY Plug lead kits then ? NigerPS May not cure it but they sure do look preedy Quote Link to comment Share on other sites More sharing options...
team_wingnut Posted March 18, 2012 Author Share Posted March 18, 2012 Want me to send you one of my nice DIY Plug lead kits then ? NigerPS May not cure it but they sure do look preedy Tell you what, I'll get the measurements I Need, can you put the ends on? obviously I will pay for the time of making them Quote Link to comment Share on other sites More sharing options...
elbekko Posted March 18, 2012 Share Posted March 18, 2012 Have you done a compression test? Have you tried with a spark plug outside the block to get a look at the spark? Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted March 18, 2012 Share Posted March 18, 2012 How much work is involved in swapping injectors themselves over? That would prove/disprove Nigels theory. This will show my complete ignorance of Land Rover V8's as you tell me it would be easier to swap conrods ....... Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 18, 2012 Share Posted March 18, 2012 Swapping injectors on the even side is pretty easy, less so the ones under the plenum. Quote Link to comment Share on other sites More sharing options...
team_wingnut Posted March 20, 2012 Author Share Posted March 20, 2012 Have you done a compression test? Have you tried with a spark plug outside the block to get a look at the spark? Yes got compression, yes, got a belting spark comming out of lead. Going to increase the plug gaps at the weekend, open them up by .25 thou and see what its like, other than that will try swapping injectors, then if that fails, test continuity on the injector looms, and plugs. will keep everybody updated! Quote Link to comment Share on other sites More sharing options...
rusty_wingnut Posted March 21, 2012 Share Posted March 21, 2012 plug gaps? Quote Link to comment Share on other sites More sharing options...
bobtail84 Posted March 21, 2012 Share Posted March 21, 2012 I have mine at 1mm and I have no problems. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 22, 2012 Share Posted March 22, 2012 EDIS doesn't usually have a problem with plug gaps... Quote Link to comment Share on other sites More sharing options...
team_wingnut Posted March 22, 2012 Author Share Posted March 22, 2012 I think for the sake of a 2 min job, I will open them up a little and see what happens! Quote Link to comment Share on other sites More sharing options...
team_wingnut Posted March 25, 2012 Author Share Posted March 25, 2012 Ok, the update from an afternoon in the workshop yesterday... Now have tps calibrated with full values! runs miles better, as it should, for a moment thought it was running on 8! on closer inspection, no, still missing on 4 and 6! took out all plugs and compression tested, 150-160 psi on all 8, (a little lower that I would have liked but hey ho!) cleaned plugs in shotblaser (propper spark plug one) and set plug gaps to .40 thou (1mm), put them back in, no different at all. spoke with Nige, for the umpteenth time, think now its a dribbling injector, so next weekend, take off plenum and fuel rail and put two new injectors in it, see if thats it, while its all inbits would also be a good time to change my inlet manifold gasket, again as still have a small water leak, that wont go away. No before you ask, it isnt drawing air, as ive lashed up all possible areas with easy start to see if its drawing air and it isnt. While we're on the subject, what is the best inlet manifold gasket to use, ive used a composite gasket until now, but going to try a tin one, as I have one on the shelf, and because ive used the thinner tin headgaskets and using composite inlet gasket makes all the blot holes tighter as the gasket is slightly thicker! Failing all that 300tdi it is! Quote Link to comment Share on other sites More sharing options...
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