Careless Posted November 21, 2007 Author Share Posted November 21, 2007 misfiring. a lot of Skyline guys have misfire problems of all sorts. these usually fall into spark plug gap problems, or ignitor being toasted. Worn coilpacks can contribute, as well as the coilpack loom, which gets stiff and old. There are more complex situations as well such as momentary overfueling, etc. hmm, is it power surge that over pumps the fuel pump for some reason, or is it the FPR having momentary failure? either way, excess fuel is better than lack thereof in situations similar to this. =) I'll make note of that under the fuel system issues portion. Ive seen so many half assed things to get misfires working.. from those blue SuperDi Ignition kits which supposedly suck balls with super weak spark, to people coating their coils with finger nail hardener (diamond coat only!). It's rediculous, but some report good results. LS1/Suburban coils are on top of the list though =) Quote Link to comment Share on other sites More sharing options...
Guest kismetcapitan Posted November 21, 2007 Share Posted November 21, 2007 coilpacks wear out, but you can test the resistance, and if they're all spot on, you can eliminate that as a cause. Some people swear by splitfire coilpacks, and I do have a set, but I can't say I've noticed any difference. The HKS DLI Ignition does make a tangible difference in the feel of the engine for the better, and I imagine it could stave off misfires. Most of my misfire problems were plug related. Higher boost means tightening the gap, down to 0.6mm if need be. Sick of gapping, I switched to surface gap spark plugs, which are immune to preignition (essentially infinitely cold) but require a strong jolt of electricity to fire. Fiddling with the ignitor often produces results. More than one person has merely moved the ground wire to a different screw, or added a grounding kit, to get rid of misfiring. One thing I think is overlooked is an overheated head. If the coolant system has air in it, and it collects in the head, the head could overheat, while the cylinders and radiators are at normal temp. I ran into this once or twice, and will most likely use a radiator catch can with breather to avert coolant flow problems in the future. overfueling is actually a misnomer. under"airing" is more accurate. A boost leak, from a BOV or popped intercooler pipe, means that not all the air that the AFM is reading is reaching the engine. So the injectors inject fuel for air that isn't there. Running overly rich and with too much timing retard at redline can cause misfiring at the top of the powerband, i.e. over 7000rpm. One thing to watch out for is "lean misfire". Not enough fuel. I don't know a lot about it, other than that it's bad, unless your car has direct gasoline injection (which the RB does not). Quote Link to comment Share on other sites More sharing options...
Careless Posted November 22, 2007 Author Share Posted November 22, 2007 coilpacks wear out, but you can test the resistance, and if they're all spot on, you can eliminate that as a cause. Some people swear by splitfire coilpacks, and I do have a set, but I can't say I've noticed any difference. The HKS DLI Ignition does make a tangible difference in the feel of the engine for the better, and I imagine it could stave off misfires. Yeah I read good and bad from the splitfire. mostly bad though. but with remote mounted coils, at a cheaper price, and used on a car that makes way more factory horsepower and produces a way hotter spark, I think ill take the cheaper/stronger route. I will include the splitfires as an option in the japanese aftermarket section of the reference guide. Most of my misfire problems were plug related. Higher boost means tightening the gap, down to 0.6mm if need be. Sick of gapping, I switched to surface gap spark plugs, which are immune to preignition (essentially infinitely cold) but require a strong jolt of electricity to fire. surface gap same as side-gapped? Fiddling with the ignitor often produces results. More than one person has merely moved the ground wire to a different screw, or added a grounding kit, to get rid of misfiring. Yeah that's always the case with grounds. Same poo happens with car stereos that run amplifiers. So many times I have to fix broken grounds on friends cars that have installs done by some schmoes who don't use a bolt that can be fastened properly, and in an area that won't corrode rapidly. One thing I think is overlooked is an overheated head. If the coolant system has air in it, and it collects in the head, the head could overheat, while the cylinders and radiators are at normal temp. I ran into this once or twice, and will most likely use a radiator catch can with breather to avert coolant flow problems in the future. so the boil over will just fall into a can? I see that RIPS and Stony have both used resevoirs, but there seems to be no breather box that allows the air to vent off. possibly because they're drag cars or something? overfueling is actually a misnomer. under"airing" is more accurate. A boost leak, from a BOV or popped intercooler pipe, means that not all the air that the AFM is reading is reaching the engine. So the injectors inject fuel for air that isn't there. Running overly rich and with too much timing retard at redline can cause misfiring at the top of the powerband, i.e. over 7000rpm. One thing to watch out for is "lean misfire". Not enough fuel. I don't know a lot about it, other than that it's bad, unless your car has direct gasoline injection (which the RB does not). I know full well about the underfueling. Had a friend with a hyundai accent turbo who suffered a lean condition, and had nuclear meltdown. surprisingly, the aluminum head was fine, it was the block that went all warpy =/ yah. excess lean = excess heat = excess rubbery aluminum. leads to fast head warpage. These are things I will probably put in the misc section or just make small note of though. Don't want to over-fill this guide. sometimes it's too much to explain every single detail down to the size of the bubbles in the coolant. thanks for your input again, kismet Quote Link to comment Share on other sites More sharing options...
Racinjitter Posted November 22, 2007 Share Posted November 22, 2007 the lean condition in the #6 cylinder is NOT caused by heat (although heat exacerbates knock tendency in that cylinder as its the last to get coolant). It's simply the design of the intake plenum. The first five cylinders take the amount of air they want, and the last one gets stuck with any extra air...that's a basic way to look at it. Wait, so the lesser amout of air that goes into a cylinder compared to a cylinder with more air with the same amount of fuel going to both will cause a lean condition? Is that what you are saying? Or are you saying that somehow the #6 cylinder intake valves are being forced open, forcing more air into the cylinder? If you are saying that the intake design is creating more heat for # 6 cylinder it very well may help contribute to the lean condition. Quote Link to comment Share on other sites More sharing options...
Guest kismetcapitan Posted November 22, 2007 Share Posted November 22, 2007 Wait, so the lesser amout of air that goes into a cylinder compared to a cylinder with more air with the same amount of fuel going to both will cause a lean condition? Is that what you are saying? Or are you saying that somehow the #6 cylinder intake valves are being forced open, forcing more air into the cylinder? If you are saying that the intake design is creating more heat for # 6 cylinder it very well may help contribute to the lean condition. too much air gives you lean, and lean = too hot = bad. The intake valves are open for the same duration as the other valves, it's just that more air gets pushed in on #6 during boost than the other cylinders (because where else can that extra air go?) Quote Link to comment Share on other sites More sharing options...
Racinjitter Posted November 22, 2007 Share Posted November 22, 2007 Is this the same for all RB's? As the 20/25 have a completely different intake design than the 26. Is there an airflow picture of the intakes out there to comfort me? I just dont see how one cylinder could be forced into getting all of the extra air that the other cylinders didnt use. In most engines if the air isnt used by one cylinder it will be scavanged by another cylinder, no matter the location. As it goes through the firing order the engine may or may not use it. If it doesnt use the air, turbulence will be caused (not forced into another cylinder). Quote Link to comment Share on other sites More sharing options...
Careless Posted November 22, 2007 Author Share Posted November 22, 2007 i thought it was always a lack of air in the last 2 cylinders, getting progressively worse at it goes further back into the intake. That's why jun and greddy have sweeping shapes for their plenums, quite like big ron's intake he made for the blue s30 except with more concave in nature. Quote Link to comment Share on other sites More sharing options...
Guest kismetcapitan Posted November 23, 2007 Share Posted November 23, 2007 nope, excess air. a lack of air would have the #6 cylinder run rich, and that would, if anything, be ok. The problem isn't really pronounced in the RB20/RB25 because of the center plenum feed. In that case, #1 and #6 get the excess air, but it's not as bad because its evenly split, and people generally don't run the huge boost levels you see on RB26s. That being said, if you do an RB25 with a front mount intercooler, and go to an RB26-style plenum, you'll have to watch the #6 cylinder. I'm not sure about the other plenum designs, if Greddy or JUN or whoever is getting better balance, I'm only certain that the Nismo design more or less solves the problem. It's really a bit of a guessing game because, to be absolutely sure, you'd need wideband sensors on each exhaust exit, and it's a little hot there for a wideband to live long. An indirect way is to measure EGT, by having six temp probes stuck in each exhaust runner. But then having six EGT gauges in the car is a little much Also, I don't like having anything before the turbo - on the one hand, the only truly accurate EGT reading you can get is a inch or two before the turbo (because the turbo is a big heat soak), but if the sensor tip breaks off, you can kiss your turbo goodbye. The R34 Skyline has the EGT sensor immediately after the rear (hotter) turbo, so that's where I stuck mine. Quote Link to comment Share on other sites More sharing options...
Careless Posted November 23, 2007 Author Share Posted November 23, 2007 nope, excess air. a lack of air would have the #6 cylinder run rich, and that would, if anything, be ok. The problem isn't really pronounced in the RB20/RB25 because of the center plenum feed. In that case, #1 and #6 get the excess air, but it's not as bad because its evenly split, and people generally don't run the huge boost levels you see on RB26s. That being said, if you do an RB25 with a front mount intercooler, and go to an RB26-style plenum, you'll have to watch the #6 cylinder. I'm not sure about the other plenum designs, if Greddy or JUN or whoever is getting better balance, I'm only certain that the Nismo design more or less solves the problem. It's really a bit of a guessing game because, to be absolutely sure, you'd need wideband sensors on each exhaust exit, and it's a little hot there for a wideband to live long. An indirect way is to measure EGT, by having six temp probes stuck in each exhaust runner. But then having six EGT gauges in the car is a little much Also, I don't like having anything before the turbo - on the one hand, the only truly accurate EGT reading you can get is a inch or two before the turbo (because the turbo is a big heat soak), but if the sensor tip breaks off, you can kiss your turbo goodbye. The R34 Skyline has the EGT sensor immediately after the rear (hotter) turbo, so that's where I stuck mine. I was thinking of installing 6 thermocouples in the runners for my dirty-30, and wrapping the exhaust pipes in some header wrap. Quote Link to comment Share on other sites More sharing options...
g00kb0i Posted November 26, 2007 Share Posted November 26, 2007 http://tyndago.googlepages.com/rb26dettinformation Quote Link to comment Share on other sites More sharing options...
Careless Posted November 26, 2007 Author Share Posted November 26, 2007 well well well , thanks for the link =) Got some great info there! Is'at your page? http://tyndago.googlepages.com/rb26dettinformation Quote Link to comment Share on other sites More sharing options...
scottyMIz Posted November 30, 2007 Share Posted November 30, 2007 good idea careless, i havent been on in a while so i just saw this post as well as others. As far as the lean #6 cyl i will tell you when i run a compression test on mine. I broken mine this year and i didn't check which piston took the hit. I built my own intake log style and i will check to see which one took a crap on me. I know with the L28et the first cyls to take a crap were numbers 1-2, not sure which one/s died on me this time. It was my fault it broke but i just chalk it up to expirence Also if you want any info on haltechs on the rb's careless i have what i went thru to offer. Quote Link to comment Share on other sites More sharing options...
Careless Posted November 30, 2007 Author Share Posted November 30, 2007 good idea careless, i havent been on in a while so i just saw this post as well as others. As far as the lean #6 cyl i will tell you when i run a compression test on mine. I broken mine this year and i didn't check which piston took the hit. I built my own intake log style and i will check to see which one took a crap on me. I know with the L28et the first cyls to take a crap were numbers 1-2, not sure which one/s died on me this time. It was my fault it broke but i just chalk it up to expirence Also if you want any info on haltechs on the rb's careless i have what i went thru to offer. That's great to hear that you've got some info, scotty. Sad thing about the RB25 though =( As long as you had fun with it =) I also hear that you're looking for an RB30. Seems like a handful of people are after this RB30 that's sitting at the back of my friend's shop. I'll be getting pictures and sending them to everyone. First one to take a bit gets it. I'll be postponing the guide until the Christmas break. That's when I'll be at my parents house for a nice lengthy period of time, so I can really sit down and get'r rollin. Possibly host soemthign on the website while I'm at it too =) Thanks for you support, everyone! Quote Link to comment Share on other sites More sharing options...
scottyMIz Posted December 1, 2007 Share Posted December 1, 2007 That's great to hear that you've got some info, scotty. Sad thing about the RB25 though =( As long as you had fun with it =) I also hear that you're looking for an RB30. Seems like a handful of people are after this RB30 that's sitting at the back of my friend's shop. I'll be getting pictures and sending them to everyone. First one to take a bit gets it. I'll be postponing the guide until the Christmas break. That's when I'll be at my parents house for a nice lengthy period of time, so I can really sit down and get'r rollin. Possibly host soemthign on the website while I'm at it too =) Thanks for you support, everyone! yea i had a blast that lil motor takes a hell of a beating and hauled arse in the process. Yep i am interested in it jitter just let me know u had one along with a buddy of yours. Pm me what you want for it if he is getting one from your buddy and i get yours then we are gonna come together i think. Quote Link to comment Share on other sites More sharing options...
Careless Posted December 1, 2007 Author Share Posted December 1, 2007 There's only one RB30 available... and there are 4 people that have asked me for it. I have my other RB30 that had a slump in the main skirt casting. I think it would still be good, but I'm not the type to chance it. I got pics sent today, but they were linked to the sender's web-mail, and not attached directly... so I can't see them. LOL Quote Link to comment Share on other sites More sharing options...
scottyMIz Posted December 2, 2007 Share Posted December 2, 2007 So the one with the slump in the main skirt is the one your selling? Quote Link to comment Share on other sites More sharing options...
Careless Posted December 2, 2007 Author Share Posted December 2, 2007 lol. it's available, but it's not the one. THE ONE everyone wants has been photographed and sent to my email. I'm typing this from my iPod Touch, so I can't send you the pictures just now. Anyway, the fairly good block is only rusted from sitting outside. The oil pan is still on there and everything but the head and all the external parts are not included. It's gonna need a hot tanking FOR SURE, and a bore/hone... so get some oversized pistons if you want it. I'll send the pics later, I'm going to pick up my Z31 in this shittay weather. Any more questions about the block, please PM me. Quote Link to comment Share on other sites More sharing options...
Careless Posted February 10, 2008 Author Share Posted February 10, 2008 Hi Gents, I've started to edit some of the pics for the part numbers that I have. And I've sent the link to someone else for some feedback (Shhhhh!, you!) so I'll be cleaning up and watermarking the pics so they look nice and presentable, and then I will post the part numbers as well as where they go. They will be posted on one of my websites so you guys can access it easily and purchase parts that you need through your nissan dealer by using the provided part numbers. I hope this helps you guys find parts that you need. I cannot guarantee that everything will fit, because I have yet to put my engine together, and because it is a weird combo (RB30/26), so some parts are from here, some are from there... and some are aftermarket. Hope to make some good progress this week. Cheers, Raff Quote Link to comment Share on other sites More sharing options...
Wedge Posted February 11, 2008 Share Posted February 11, 2008 You could try and gather info about the RB on GTRC forum ( http://forums.gtrcanada.com/ ) the guys there are VERY helpfull you probably know of that forum but im just putting it out there since lots of knowledge is held by some members there . I know you said you dont like visiting a gazillion sites but a quick search here and there could probably shed some light on your inquiry's . Quote Link to comment Share on other sites More sharing options...
Careless Posted February 11, 2008 Author Share Posted February 11, 2008 You could try and gather info about the RB on GTRC forum ( http://forums.gtrcanada.com/ ) the guys there are VERY helpfull you probably know of that forum but im just putting it out there since lots of knowledge is held by some members there . I know you said you dont like visiting a gazillion sites but a quick search here and there could probably shed some light on your inquiry's . And you are right. I know of that site, and I've not yet searched odds and ends, but for now what I'm doing is taking pictures of my parts that I've bought. I've got well over 240 pictures, each with different angles of each part. Water Pump Pulley, Crank Balancers, Bolts, Washers, Dowels, Pins, Bushings... a bunch of stuff to freshen the RB blocks up if going from ground zero to fully built. I'm taking my notes as to how many I'm using per engine, so that I can put together a kit if anyone would like them. This won't happen for a while. The website is taking priority over a bunch of other things. I'm just having trouble deciding on what logo to use to brand my pictures from what theft that other sites may commit. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.