team stevedave Posted July 11, 2015 Share Posted July 11, 2015 (edited) Hi guys. So I have a vortech charged 04 zed with 57k. Just today I was out in the car and gave it a bit push on a short duel carrigeway, when approaching the roundabout I heard a whine from the engine coming down with the revs, dropped a gear and done the same. When I then stopped at the next roundabout the idle became very rough, a missfire I expect. Occasionally over reving to stop it cutting out. Now after limping home I let the car cool and started again, idle is still incredibly lumpy with a really bad missfire. Slowly bringing the revs up still misfiring at 2500k, but with normal reving seems fine. After letting the revs drop. I glanced at my gauges fuel pressure is altering from 3.5 - 6 which is normal when under load but not idle, and air fuel ratio was sitting very lean at 16.5-1 and would drop going up the revs. It should be noted I already have a code for sensor 2 bank 2 lambda, which has always been there on ownership and never caused a problem. Usually sitting at 14.6 - 14.8 a/f on average driving and around that on idle. So as you can imagine I'm a little sad my pride and joy is sick and would love some thoughts from you guys to help me on my way through fault finding. Also Iv pulled a couple coil plugs out while running to try hear for a change but seems to make no difference!?? My work has an ethos I will be plugging into to check for any new codes on Monday, which I'm guessing may return with a P0300 random missfire. Any help would be hugely appreciated guys. And I sincerely apologise for the essay. David Edited July 11, 2015 by team stevedave Quote Link to comment Share on other sites More sharing options...
Sam Mcgoo Posted July 11, 2015 Share Posted July 11, 2015 It does sound like your running lean, causing the missfire. As you said, should be idling at around 14.7. If it was a plug or coil pack it would normally run rich. Any smoke ? Have you got an OBD2 reader? on your phone or anything? Can be invaluable for fault finding looking at fuel trims etc. What bank is your AFR gauge plumbed into? What fuel system and injectors do you have? Could also be a vacuum/boost leak so carefully check all your pipework for cracks, leaks, tight fittings. Have a read through my thread here from when I was diagnosing a missfire on my supercharged Zed. Should help a lot. http://www.350z-uk.com/topic/78240-running-lumpy-no-eml-all-sorted/page__hl__lumpy Quote Link to comment Share on other sites More sharing options...
team stevedave Posted July 11, 2015 Author Share Posted July 11, 2015 Cheers for the reply. I have a snap-on ethos code reader at my work I can plug into. After a good inspection there is a part of gasket blown out bout 10mm at the front of the kinetix plenum, but doesn't look that fresh tbh, I'm hoping this may be the cause. I believe kinetix gaskets can be hard to source tho. Maybe just try gasket sealer for now. As for smoke I haven't noticed anything but my girl says she noticed some when passing her work. But let's not take that too seriously (females) And I'm actually unsure on fueling I'm afraid. I'm actually hoping to find out from previous owners on this forum as iv been told its been around on here before. Quote Link to comment Share on other sites More sharing options...
team stevedave Posted July 11, 2015 Author Share Posted July 11, 2015 Oh and can't quite remember what side the AFR is on but I'm sure its the opposite side of the faulty cat/lamda so bank 1 I'd imagine. Quote Link to comment Share on other sites More sharing options...
team stevedave Posted July 11, 2015 Author Share Posted July 11, 2015 Quote Link to comment Share on other sites More sharing options...
Keyser Posted July 12, 2015 Share Posted July 12, 2015 I was going to post that it sounded like an air leak as Sam has said above, but it looks like you found it Hopefully a new gasket and back on the road Quote Link to comment Share on other sites More sharing options...
Wasso Posted July 12, 2015 Share Posted July 12, 2015 If you find this is gasket related, I can get one made for you, or at least get you some contact details to have one specially made of you cannot source one for love nor money. You would need to send them your Kinetix and they would scan the dimensions needed. As its a one off it won't be cheap, but I could probably chat with them to at least accommodate the emergency needs and they may reduce their costs. Quote Link to comment Share on other sites More sharing options...
Mark@Abbey m/s Posted July 12, 2015 Share Posted July 12, 2015 Would just be a stock shaped gasket. Def causes the lean idle mixture and a misfire thou due to massive un metered air leak Quote Link to comment Share on other sites More sharing options...
Wasso Posted July 12, 2015 Share Posted July 12, 2015 Of course sorry have a bad head this morning. I've got spare gaskets send me a PM and I can send you one. Quote Link to comment Share on other sites More sharing options...
team stevedave Posted July 12, 2015 Author Share Posted July 12, 2015 Just put my thumb over the leak and it idles fine. Thank God for that! Thanks to everyone that replied to help me through. Would you recommend replacing the gasket or use sealer. Or both? Quote Link to comment Share on other sites More sharing options...
Keyser Posted July 12, 2015 Share Posted July 12, 2015 Just put my thumb over the leak and it idles fine. Thank God for that! Thanks to everyone that replied to help me through. Would you recommend replacing the gasket or use sealer. Or both? Replace the gasket with an OEM should be no need for anything else Sealant will only be a temp fix but you will probably blow it out again due to boost Quote Link to comment Share on other sites More sharing options...
team stevedave Posted July 12, 2015 Author Share Posted July 12, 2015 Ye that's why I thought sealer may be a better option as the OEM (paper?) Gasket may only be designed to hold atmospheric pressure and the charger will be forcing air into the plenum. Quote Link to comment Share on other sites More sharing options...
Keyser Posted July 12, 2015 Share Posted July 12, 2015 OEM (Nissan) gasket on the plenum is not paper - that's the one you want you may have a kinetix gasket if it's a kinetix plenum ??? Quote Link to comment Share on other sites More sharing options...
Keyser Posted July 12, 2015 Share Posted July 12, 2015 Just to add I ran the OEM on my SC 350 with NOS (over 500HP at the wheels) never blew that gasket - blew a couple of hoses off though Quote Link to comment Share on other sites More sharing options...
team stevedave Posted July 12, 2015 Author Share Posted July 12, 2015 ^^^ omg haha. Sounds FEROCIOUS! 1 Quote Link to comment Share on other sites More sharing options...
Keyser Posted July 12, 2015 Share Posted July 12, 2015 ^^^ omg haha. Sounds FEROCIOUS! O it was : Quote Link to comment Share on other sites More sharing options...
team stevedave Posted July 12, 2015 Author Share Posted July 12, 2015 I need to find my full spec on this car as I was inadequately informed when I bought her. Was told it just needs uprated fuel rail and injectors to reach 400bhp supposedly running 350 just now, but no dyno which I rekon should be on the cards. Do u think it's sensible/reliable to push for that? I love the reliability of her ( he says with a blown gasket. >_> Quote Link to comment Share on other sites More sharing options...
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