mat1227 1 Posted April 5, 2008 Still suffering a misfire on my zx16v - can anyone tell me the correct plug gap for this engine? In metric ideally much appreciated Share this post Link to post Share on other sites
welshpug 1,657 Posted April 5, 2008 just buy new plugs at the correct spec and job jobbed (plugs are now pre-gapped and shouldn't be adjusted) Share this post Link to post Share on other sites
mat1227 1 Posted April 6, 2008 thanks mate - you're fast becoming my personal zx 16v consultant for all your xu needs I've just got generic Bosch plugs from gsf (zx 16v fitment) and my mate is insisting the gap needs to be set as they are made for a range of cars - is he barking up the wrong tree? Share this post Link to post Share on other sites
205toby 0 Posted April 6, 2008 FYI the book gap is .8mm Share this post Link to post Share on other sites
brumster 135 1 Cars Posted April 6, 2008 Have not set plug gaps for years now - straight out of the box and straight into the engine has always done me fine of recent years Ah takes me back to my A-Series days Share this post Link to post Share on other sites
welshpug 1,657 Posted April 6, 2008 thanks mate - you're fast becoming my personal zx 16v consultant for all your xu needs I've just got generic Bosch plugs from gsf (zx 16v fitment) and my mate is insisting the gap needs to be set as they are made for a range of cars - is he barking up the wrong tree? wrong forest if they're in the book for the Zx (and 2.0 Mi16, S16, Xantia VSX) they'll be the right gap (0.8mm as toby said) Share this post Link to post Share on other sites
mat1227 1 Posted April 6, 2008 Ha ha dropped them in, difference was night and day car pulled great for first 40 or so miles.awesome - car's pretty quick actually.. but... towards the end of the trip the car was chuntering and missing again, on and off but more on than off. Grr. Share this post Link to post Share on other sites
welshpug 1,657 Posted April 6, 2008 tried pulling a plug off a coilpack when its doing so? what were the old plugs like? (were they blackened) I had a quick flick through the NGK catalogue earlier and the part number IIRC was BKR6EK, with no gap specified (pre-set) Share this post Link to post Share on other sites
VisaGTi16v 1 Posted April 7, 2008 Have you changed the coil packs like I suggested? That happened to me a few times and its almost certainly the cause of the problem. When one is failing it will quite often work ok until its hot. Changing the plugs will have disturbed it so again it may then start to work ok for a bit before failing again Share this post Link to post Share on other sites
mat1227 1 Posted April 7, 2008 Thanks chaps tried pulling a plug off a coilpack when its doing so? what were the old plugs like? (were they blackened) Yep tried this first - car was idling fairly normally, plug cover off, I unplugged coil pack one, it chuntered and missed noticably, plugged back in and smooth again. The same for the other three - this lead me to conclude coil packs were not at fault? I'm no expert as this is probably the first set of used spark plugs I've every actually looked at, but I'd say the tips of the plugs looked chalky yellow/cremey rather than blackened? I had a quick flick through the NGK catalogue earlier and the part number IIRC was BKR6EK, with no gap specified (pre-set) Ok thanks for that, happy no gap adjustment is required think my mate is a bit old fashioned.. Have you changed the coil packs like I suggested? That happened to me a few times and its almost certainly the cause of the problem. When one is failing it will quite often work ok until its hot. Changing the plugs will have disturbed it so again it may then start to work ok for a bit before failing again Having tested the coil packs as above, I didn't want to start with changing the coil packs for £90 or so if I could get away with swapping plugs etc initially, but it's looking like this is the next port of call. Your point about failing being more pronounced when the car is hot would explain what is going on, as I did the test when the car was fairly cold. To be honest the coil pack at the drivers side of the engine seems to get bashed a bit every time you take the metal cover on and off (a bit of leverage required unless you want to disconned fuel hoses) - and this pack on mine feels slightly looser/wobblier than the others. I did ask on here if anyone had a good known one I could try to work out which is the problem but no joy Reckon I can get three coil packs cheaper than GSF anywhere? Worth biting the bullet to get the car firing properly again (least of all because £20 of petrol gets me about 100 miles with the misfire as it is... Cheers everyone Share this post Link to post Share on other sites
welshpug 1,657 Posted April 7, 2008 (edited) £20 of petrol is about 4 gallons, 25mpg, not that bad!! IIRC the GSF price is £90 for all 4 (or maybe it was ECP) either way its the only way to sort it out really. bear in mind that if its not burning the fuel in any particular cylinder you're risking bore wash, ultimate way to kill off an engine Edited April 7, 2008 by welshpug Share this post Link to post Share on other sites
mat1227 1 Posted April 7, 2008 (edited) Ah no worries I'll do that. Thanks mate. 25mpg for a hot hatch that has all the get up and go of a polo bluemotion is not a fair return Edited to add: not done many miles at all with it like this thankfully will sort before I drive it again. Mat Edited April 7, 2008 by mat1227 Share this post Link to post Share on other sites
VisaGTi16v 1 Posted April 7, 2008 There are some on ebay at the moment. Second hand ones that are sold as having been working fine normally only go for £5 each... Share this post Link to post Share on other sites
mat1227 1 Posted April 7, 2008 Just what I'm looking at as we speak will follow this route first Share this post Link to post Share on other sites
