Jump to content
SAU Community

Recommended Posts

Hey all

I can't take it anymore with the issue and its time for DIY and learn and save $$$. I drive a r34 4door rb25de neo manual

Firstly i would like to say last year before the end of November i bought new spark plugs and had them replaced because the rocket cover gasket needed to be replace so might as well change of the spark plugs as well. With this change the car has been running perfectly without a beat until last week.

I have been noticing the car was causing some issues after roughly 10-15minutes of driving from cold start, it was coughing and losing power, it took a bit to notice but then become a lot more noticeable during cold starts and honestly felt like it was misfiring. After some time driving and the tempt reaches normal the engine runs smoothly and no misfire at all.

So here it is, I would like to know how can i go on and diagnose the problem and try and fix it, without having the diagnostic tools and electronics.

From reading through different posts, the most common places to check are the spark plugs and the coil packs, that is all i know.

I do not own a lot of tools as well if it comes down to having something really specific to fix it. (I do have a torque wrench lol)

Edited by kresot9

First of all: Rocket covers...... no. Just no. They are ROCKER covers when the car has a rocker setup. RB25's run OHC with no rocker setup, so they are actually just cam covers

What spark plugs did you use? Have you tried having a look at the cold start valve? Is it plugged in and getting power? Are the lines to it OK etc?

If it runs 100% when warm then it has to be something that is only operating on cold start (like the cold start valve, i think the AAC will also be more active at cold start)

my bad, it wasn't intentional just finger slipped the R and T are close :P

With spark plugs i got these ones 'Iridium Option BKR5EIX-11' which was from 'http://www.sau.com.au/forums/topic/32825-na-skyline-spark-plug-numbers/'

Silly questions, where and how do i check the cold start valve and the plugs, also it runs 100% when warm even driving it for 45mins it was good, the AAC? if you do not mind explaining also

thanks

Pull the plugs out and have a look at the colour of them. Brown is good, black means they're fouling and white means they're getting too hot. Check cold start valves as mentioned. Next thing to look at would be coil packs.

Have you got an error code? There's a thread somewhere which shows you how to read the error code using just a safety pin with the fuse box.

Unlikely to be plugs or coils.

Could be the ecu temp sensor. If you look where the top hose meets the block you will see two temp sensors. One has one wire (that's for your temp gauge) and the other has two wires - that's the one that goes to the ecu. I don't know of any easy way to test it but they are not too expensive to replace if you get one from an auto parts shop or auto electrician rather than Nissan.

But before you do that (if you are poor) you could try cleaning the AAC valve. This is a fiddly job but it doesn't cost any money. There at least two tutorials on how to do it.

Here's one (don't know if it applies to the Neo but you'll soon find out:

http://www.sau.com.au/forums/topic/110431-diy-aac-valve-cleaning-idle-reset/

  • 2 weeks later...

i bought myself some new coil packs but im a bit edgey with the caution they are stating after installing the split fire 008 coil packs

That the ignition timing may be needed to be done due to the increase of ignition energy and it will also cause a loud knocking sound.

Anyone else seen this on their installation papers before and should i need to worry?

i bought myself some new coil packs but im a bit edgey with the caution they are stating after installing the split fire 008 coil packs

That the ignition timing may be needed to be done due to the increase of ignition energy and it will also cause a loud knocking sound.

Anyone else seen this on their installation papers before and should i need to worry?

Don't stress. Just put them in. They won't change anything. I suppose they have to make them sound superior somehow lol.

You are not altering Ignition timing by installing new coilpacks. There is a chance that the poor coilpacks have had an increased dwell time. But the car would not have been tuned on crap coilpacks so putting new ones in should just make it as good as it was when it was tuned

If its on stock ECU, nothing at all to worry about. Change the coilpacks, do an ECU reset and all should be well

Well thanks everyone, i did the job and definitely saved some money doing it my self, the test drive seemed good without any weird sounds or disturbances in the power so will see how it goes for the weekend.

Thanks all!

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

    • Well, after the full circus this week (new gearbag, 14 psi actuator on, injectors and AFM upgraded, and.....turbo repair) the diagnosis on the wastegate is in. It was broken. It was broken in a really strange way. The weld that holds the lever arm onto the wastegate flapper shaft broke. Broke completely, but broke in such a way that it could go back together in the "correct" position, or it could rearrange itself somewhere else along the fracture plane and sit with the flapper not parallel to the lever. So, who knows how and when exactly what happened? No-one will ever know. Was it broken like this the first time it spat the circlip and wedged itself deep into the dump? Or was it only broken when I tried to pry it back into place? (I didn't try that hard, but who knows?). Or did it break first? Or did it break between the first and second event of wierdness? Meh. It doesn't matter now. It is welded back together. And it is now held closed by a 14 psi actuator, so...the car has been tuned with the supporting mods (and the order of operations there is that the supporting mods and dyno needed to be able to be done first before adding boost, because it was pinging on <<14 psi with the new turbo with only a 6 psi actuator). And then tuned up a bit, and with the boost controller turned off throughout that process. So it was only running WG pressure and so only hit about 15-16 psi. The turbo is still ever so slightly lazier than might be preferred - like it is still a bit on the big side for the engine. I haven't tested it on the road properly in any way - just driven it around in traffic for a half hour or so. But it is like chalk and cheese compared to what it was. Between dyno numbers and driving feedback: It makes 100 kW at 3k rpm, which is OK, could be better. That's stock 2JZ territory, or RB20 with G series 550. It actually starts building boost from 2k, which is certainly better than it did recently (with all the WG flapper bullshit). Although it's hard to remember what it was like prior to all that - it certainly seems much, much better. And that makes sense, given the WG was probably starting to blow open at anything above about 3 psi anyway (with the 6 psi actuator). It doesn't really get to "full boost" (say 16 psi) until >>4k rpm. I am hopeful that this is a feature of the lack of boost controller keeping boost pressure off the actuator, because it was turned off for the dyno and off for the drives afterward. There's more to be found here, I'm sure. It made 230 rwkW at not a lot more than 6k and held it to over 7k, so there seems to be plenty of potential to get it up to 250-260rwkW with 18 psi or so, which would be a decent effort, considering the stock sized turbo inlet pipework and AFM, and the return flow cooler. According to Tao, those things should definitely put a bit of a limit on it by that sort of number. I must stress that I have not opened the throttle 100% on the road yet - well, at least not 100% and allowed it to wind all the way up. It'll have to wait until some reasonable opportunity. I'm quite looking forward to that - it feels massively better than it has in a loooong time. It's back to its old self, plus about 20% extra powers over the best it ever did before. I'm going to get the boost controller set up to maximise spool and settle at no more than ~17 psi (for now) and then go back on the dyno to see what we can squeeze out of it. There is other interesting news too. I put together a replacement tube to fit the R35 AFM in the stock location. This is the first time the tuner has worked with one, because anyone else he has tuned for has gone from Z32 territory to aftermarket ECU. No-one has ever wanted to stay Nistuned and do what I've done. Anyway, his feedback is that the R35 AFM is super super super responsive. Tiny little changes in throttle position or load turn up immediately as a cell change on the maps. Way, way more responsive than any of the old skool AFMs. Makes it quite diffifult to tune as you have to stay right on top of that so you don't wander off the cell you wanted to tune. But it certainly seems to help with real world throttle response. That's hard to separate from all the other things that changed, but the "pedal feel" is certainly crisp.
    • I'm a bit confused by this post, so I'll address the bit I understand lol.  Use an air compressor and blow away the guide coat sanding residue. All the better if you have a moisture trap for your compressor. You'd want to do this a few times as you sand the area, you wouldn't for example sand the entire area till you think its perfect and then 'confirm' that is it by blowing away the guide coat residue.  Sand the area, blow away the guide coat residue, inspect the panel, back to sanding... rinse and repeat. 
    • The detail level is about right for the money they charge for the full kit... AU$21.00 each issue, 110 issues for a total of $2,300 (I mentioned $2.2K in the first post when the exchange rate was better). $20/week is doable... 😐
    • If planning on joining us for the day(s) please indicate by filling in this form. https://forms.gle/Ma8Nn4DzYVA8uDHg7
    • You put the driver's seat on the wrong side! Incredible detail on all of this. It looks like you could learn a lot about the car just from assembling the kit.
×
×
  • Create New...