Jump to content
SAU Community

Recommended Posts

hello i have a few problems with my Nissan skyline r34 gtt. when its under boost around 4600 rpm to 6000 rpm it is jumping around and kicks in and out. now i just check the spark plugs and they look stuff when they only not even 500ks old. has been tracked once and that's all. i just wondering if i could get some help out here.

.

Link to comment
https://www.sau.com.au/forums/topic/442403-rb25det-boost-jumping/
Share on other sites

So you have a misfire at the most common room range ever discussed on this site?

Search and find your answer....

Or should we all guess randomly why your car is missing?

Seriously, search first. If for some crazy reason you can't find the information ask the question then.

And if you do need more help, specify what mods your car has. That will save people making wild guesses about the situation,and will show you are willing to take the time to help the people that are trying to help you.

I'll add a wild guess in, for fun. You are running more than 10 psi on stock ecu.

  • Like 1

So you have a misfire at the most common rpm range ever discussed on this site?

Search and find your answer....

Or should we all guess randomly why your car is missing?

Seriously, search first. If for some crazy reason you can't find the information ask the question then.

And if you do need more help, specify what mods your car has. That will save people making wild guesses about the situation,and will show you are willing to take the time to help the people that are trying to help you.

I'll add a wild guess in, for fun. You are running more than 10 psi on stock ecu.

Edited by superben

sorry mate but a had look!.

new on this alright. and no i am not running 10psi. its running stock .also stock ecu

next thing the plugs gone.

it doesn't back firer it just stopping boost and jumping

So your car is 100 percent stock?

It really sounds like when boost is too high on stock ecu.

It could be coil packs as they crap out around this age of the car.

Do the usual things, clean and inspect cool packs, reduce plug gap to .7 mm, clean afm.

Do you have a boost gauge? I would check your waste gate lines are in good shape and not split which would cause higher boost.

so your thinking its boost oscillation.

yes it does have a boost gauge but it is off never on. well the spark plugs are really dark and having rust all over it as well. thanks mate

ya i have a look today then.

the car has only done 88000ks. plus it sit for over 3 years. but when the car has been running for a long time it does clear up a little

As I wrote I'm also thinking you are actually running higher boost than you think.

Turbos don't stuff up and make boost jump. Something else is the problem.

Also , check for leaks in the pipework,loose clamps etc. The only way to be completely sure of no boost leaks is to pressure test,so I suggest you Google how to pressure test intercooler pipe work. A boost leak would make it run way too rich and would cause the ecu to cut as you have described.

If it was coil packs, it would certainly pull the engine light & code 21 (primary ignition signal). Engine light will also stay on till code is actually cleared.

Is the engine light on?

Question 1: Does the problem mainly occur in second gear when going for wide open throttle?

Question 2: Does it boost ok at 4psi (stock boost level) BELOW 4,000rpm?

gavin when its below 4000 rpm its fine.

i think ben maybe right the is something making more boost or a leak.

but a month ago when i taken it for a drive the boost garage was hitting over 1k..

wtf the dam computer posted my comment when i wasn't finished.

what it was meant to say the boost garage was hitting over 1kg/cm on the stock garage then my boost garage was geting over 1.27kg/cm i am not sure if it meant to go that high ???? .

oh k well for plugs i have (PFR6G-11)

Google what that is in psi.......

Now you can see why trying to diagnose and help people over the net is a frustrating thing.

And the record shows my first guess to be correct..... what an achievement ;)

Edited by superben

Read my first post.

I can't believe I have to spell it out.

You are running to much boost.

Stock ecu has a spaz over 12psi.

You are running over 14 psi, yet in your first reply said stock boost when I guessed that you were running over 10 psi.

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

    • The rain is the best time to push to the edge of the grip limit. Water lubrication reduces the consumption of rubber without reducing the fun. I take pleasure in driving around the outside of numpties in Audis, WRXs, BRZs, etc, because they get all worried in the wet. They warm up faster than the engine oil does.
    • When they're dead cold, and in the wet, they're not very fun. RE003 are alright, they do harden very quickly and turn into literally $50 Pace tyres.
    • Yeah, I thought that Reedy's video was quite good because he compared old and new (as in, well used and quite new) AD09s, with what is generally considered to be the fast Yokohama in this category (ie, sporty road/track tyres) and a tyre that people might be able to use to extend the comparo out into the space of more expensive European tyres, being the Cup 2. No-one would ever agree that the Cup 2 is a poor tyre - many would suggest that it is close to the very top of the category. And, for them all to come out so close to each other, and for the cheaper tyre in the test to do so well against the others, in some cases being even faster, shows that (good, non-linglong) tyres are reaching a plateau in terms of how good they can get, and they're all sitting on that same plateau. Anyway, on the AD08R, AD09, RS4 that I've had on the car in recent years, I've never had a problem in the cold and wet. SA gets down to 0-10°C in winter. Not so often, but it was only 4°C when I got in the car this morning. Once the tyres are warm (ie, after about 2km), you can start to lay into them. I've never aquaplaned or suffered serious off-corner understeer or anything like that in the wet, that I would not have expected to happen with a more normal tyre. I had some RE003s, and they were shit in the dry, shit in the wet, shit everywhere. I would rate the RS4 and AD0x as being more trustworthy in the wet, once the rubber is warm. Bridgestone should be ashamed of the RE003.
    • This is why I gave the disclaimer about how I drive in the wet which I feel is pretty important. I have heard people think RS4's are horrible in the rain, but I have this feeling they must be driving (or attempting to drive) anywhere close to the grip limit. I legitimately drive at the speed limit/below speed the limit 100% of the time in the rain. More than happy to just commute along at 50kmh behind a train of cars in 5th gear etc. I do agree with you with regards to the temp and the 'quality' of the tyre Dose. Most UHP tyres aren't even up to temperature on the road anyway, even when going mad initial D canyon carving. It would be interesting to see a not-up-to-temp UHP tyre compared against a mere... normal...HP tyre at these temperatures. I don't think you're (or me in this case) is actually picking up grip with an RS4/AD09 on the road relative to something like a RE003 because the RS4/AD09 is not up to temp and the RE003 is closer to it's optimal operating window.
    • Either the bearing has been installed backwards OR the gearbox input shaft bearing is loosey goosey.   When in doubt, just put in a Samsonas in.
×
×
  • Create New...