Jump to content
SAU Community

Recommended Posts

I was wondering if anyone knows how to fix my gtr. When i start it up its fine, leave it to warm up its fun, but say 15 mins into driving it it starts to splutter and hesitate whenever coming on boost, like it is dropping a cylinder, then it'll drop a cylinder alltogether and run on 5. After that happens it wont rev above 2000rpm without all the cylinders cutting in and out making the whole car shudder, i have no idea what it could be. I have cleaned the afm's, changed spark plugs, the next on the list is cleaning the electric connections to the coils and temp sensor with some cleaner. Can anyone shed some light onto what might be happening? The motor has a blitz induction kit, exhaust and clutch, its pretty much stock.

Link to comment
https://www.sau.com.au/forums/topic/85472-help-needed-bnr32-gtr/
Share on other sites

Guest Variable

Dead coil pack.

Next time it happens, pull over and while the engine is still running unplug one coil pack at a time. When you find the one where the idle does not change, you're got the culprit.

In preparation for this, you might want to remove the coil pack cover (if you haven't already)

I don't know much about these engines, but mine did a similar thing when I changed the plugs recently. Check the connection on the cdi at the back of your engine, mine was not on properly and ran like a dog. You could notice the difference when you wiggle the connection at the back.

Hope this helps!

Thanks for the sugestions guys, i will check the connections and try cleaning the plugs with an electrical cleaner incase they're dirty. I had a feeling in might be that connection, i might go to my mechanic and get him to test how stong the spark is to each coil just incase. I've also noticed that generally the exhaust note and idle not of the car has charged, its sounds lumpier and crap even when just starting up the car..

Edited by Dynamix

I'm having same issue. EVERYONE loves to say coils. Not only that, they don't seem to take any other idea as an option, but coils would normally break down when cold, rather than hot.

You really do need to check coils as well as ignitor, but my money is on ignitor.... when my ignitor finally arrives in the mail, we'll see.

To check coils, check resistance with a multi meter. Pin on Left to Pin in center, should read as little resistance as possible. Around 0.7

From the Pin on the right, to the spring which attaches to top of plug, resistance should be infinite.

i have my money on igniter.....heres what you do to check......run it until it does it...then pull over and let it idle and pull each injector plug off untill you find the dead cylinder....then change the dead cylinders coil with a good cylinders one.....repeat the test again and if it happens again on the same cylinder...its the igniter.....the ecu can also cause this but i reckon the igniter is crook

Hrm cleaned and pulled apart all the coils and ignighter, its seems to be running and idling slightly smoother then drops a cyl again after it starts to heat up a fair bit. Also pu another set of brand new spark plugs in again. I can get my hands of a set of rb25 coils for free, will they work in the rb26? I'll keep trying those idea's, thanks for the feedback guys.

Dead coil, pulled the coils off one by one and checked them when it dropped a cyl, number 5 was dead and made no difference so i swapped it with number one and then number one died and made no difference when i started it back up. Does anyone know if rb25 coils will work on the rb26, and if so will it be safe?

Easiest way to diagnose is find a friend with another R32 (rb20 uses same coils, harness and igniter as RB26 BTW) and swap out with his known good bits one at a time.

If all is swapped (including the harness - I once had a problem with the grounding lug not having a good connection) and you still have probs, check the spark plugs for cracking on the insulation.

With persistence you'll find the problem.

Edited by Gav
Easiest way to diagnose is find a friend with another R32 (rb20 uses same coils, harness and igniter as RB26 BTW) and swap out with his known good bits one at a time. 

If all is swapped (including the harness - I once had a problem with the grounding lug not having a good connection) and you still have probs, check the spark plugs for cracking on the insulation.

With persistence you'll find the problem.

Thanks for that info, very helpful! I'm getting some rb20 coils this afternoon to put in to replace the one i know is dead, i also had a feeling that it may not be grounding/earthing as good as it should be aswell, so i might get an earthing kit, or make one up. The plugs are fine, no signs of cracking but the one on the dead coil is wet looking as it would be because its not sparking, other than that they are good, they're only 3 days old. If that doesn't fix the problem i can grab a whole set of coils, igniter and harness of a mate.

Dead coil, pulled the coils off one by one and checked them when it dropped a cyl, number 5 was dead and made no difference so i swapped it with number one and then number one died and made no difference when i started it back up. Does anyone know if rb25 coils will work on the rb26, and if so will it be safe?

Coils from a S1 RB25 will work, because they use a seperate ignitor module. Coils from S2 RB25 don't work because they have inbuilt ignitors.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • First up, I wouldn't use PID straight up for boost control. There's also other control techniques that can be implemented. And as I said, and you keep missing the point. It's not the ONE thing, it's the wrapping it up together with everything else in the one system that starts to unravel the problem. It's why there are people who can work in a certain field as a generalist, IE a IT person, and then there are specialists. IE, an SQL database specialist. Sure the IT person can build and run a database, and it'll work, however theyll likely never be as good as a specialist.   So, as said, it's not as simple as you're thinking. And yes, there's a limit to the number of everything's in MCUs, and they run out far to freaking fast when you're designing a complex system, which means you have to make compromises. Add to that, you'll have a limited team working on it, so fixing / tweaking some features means some features are a higher priority than others. Add to that, someone might fix a problem around a certain unrelated feature, and that change due to other complexities in the system design, can now cause a new, unforseen bug in something else.   The whole thing is, as said, sometimes split systems can work as good, and if not better. Plus when there's no need to spend $4k on an all in one solution, to meet the needs of a $200 system, maybe don't just spout off things others have said / you've read. There's a lot of misinformation on the internet, including in translated service manuals, and data sheets. Going and doing, so that you know, is better than stating something you read. Stating something that has been read, is about as useful as an engineering graduate, as all they know is what they've read. And trust me, nearly every engineering graduate is useless in the real world. And add to that, if you don't know this stuff, and just have an opinion, maybe accept what people with experience are telling you as information, and don't keep reciting the exact same thing over and over in response.
    • How complicated is PID boost control? To me it really doesn't seem that difficult. I'm not disputing the core assertion (specialization can be better than general purpose solutions), I'm just saying we're 30+ years removed from the days when transistor budgets were in the thousands and we had to hem and haw about whether there's enough ECC DRAM or enough clock cycles or the interrupt handler can respond fast enough to handle another task. I really struggle to see how a Greddy Profec or an HKS EVC7 or whatever else is somehow a far superior solution to what you get in a Haltech Nexus/Elite ECU. I don't see OEMs spending time on dedicated boost control modules in any car I've ever touched. Is there value to separating out a motor controller or engine controller vs an infotainment module? Of course, those are two completely different tasks with highly divergent requirements. The reason why I cite data sheets, service manuals, etc is because as you have clearly suggested I don't know what I'm doing, can't learn how to do anything correctly, and have never actually done anything myself. So when I do offer advice to people I like to use sources that are not just based off of taking my word for it and can be independently verified by others so it's not just my misinterpretation of a primary source.
    • That's awesome, well done! Love all these older Datsun / Nissans so rare now
    • As I said, there's trade offs to jamming EVERYTHING in. Timing, resources etc, being the huge ones. Calling out the factory ECU has nothing to do with it, as it doesn't do any form of fancy boost control. It's all open loop boost control. You mention the Haltech Nexus, that's effectively two separate devices jammed into one box. What you quote about it, is proof for that. So now you've lost flexibility as a product too...   A product designed to do one thing really well, will always beat other products doing multiple things. Also, I wouldn't knock COTS stuff, you'd be surprised how many things are using it, that you're probably totally in love with As for the SpaceX comment that we're working directly with them, it's about the type of stuff we're doing. We're doing design work, and breaking world firsts. If you can't understand that I have real world hands on experience, including in very modern tech, and actually understand this stuff, then to avoid useless debates where you just won't accept fact and experience, from here on, it seems you'd be be happy I (and possibly anyone with knowledge really) not reply to your questions, or input, no matter how much help you could be given to help you, or let you learn. It seems you're happy reading your data sheets, factory service manuals, and only want people to reinforce your thoughts and points of view. 
    • I don't really understand because clearly it's possible. The factory ECU is running on like a 4 MHz 16-bit processor. Modern GDI ECUs have like 200 MHz superscalar cores with floating point units too. The Haltech Nexus has two 240 MHz CPU cores. The Elite 2500 is a single 80 MHz core. Surely 20x the compute means adding some PID boost control logic isn't that complicated. I'm not saying clock speed is everything, but the requirements to add boost control to a port injection 6 cylinder ECU are really not that difficult. More I/O, more interrupt handlers, more working memory, etc isn't that crazy to figure out. SpaceX if anything shows just how far you can get arguably doing things the "wrong" way, ie x86 COTS running C++ on Linux. That is about as far away from the "correct" architecture as it gets for a real time system, but it works anyways. 
×
×
  • Create New...