Jump to content
SAU Community

Recommended Posts

hey. i just picked up my stagea and for some reason when ever it gets ova 4000-4500 it just starts missing and not wanting to keep reving, its almost like its hitting boost cut. ive seen somewhere on here that ova 4000-4500 the boost is suposed to increase, could this cause the problem??

Link to comment
https://www.sau.com.au/forums/topic/221697-rb25neo-missingacting-weird/
Share on other sites

coil packs and or sparkplugs most probably.. either that or sum1 has previously earthed the solinoid n done a shit job.. look at the passenger side strut tower.. any thing around there got a wire cut and then earthed to the body or sumthing?

hey. i just picked up my stagea and for some reason when ever it gets ova 4000-4500 it just starts missing and not wanting to keep reving, its almost like its hitting boost cut. ive seen somewhere on here that ova 4000-4500 the boost is suposed to increase, could this cause the problem??

If you click on http://www.skylinesaustralia.com/forums/Ja...html&st=880

and scroll down to post 884 you will see a picture of a solenoid in the bottom right hand corner. If the wiring shows signs of the solenoid having been shorted out then it could be stuffed in which case it will stay closed but this is not likely to give you the symptoms you are getting. (its worth doing this mod anyway).

Coils could have been affected by the steamcleaning on import but change the plugs first as coils are expensive - perhaps see if you can borrow a set to check.

it is fully stock as far as i know. i will check the boost control tomorrow, what sort of plugs is it suposed to have. it has actually improved alot by driving it more. like sometimes it goes fine. but ocasionally it will miss.

boost solenoid is nothing to do with your miss, forget that for now...

My personal opinion, platinums...NGK recommends PFR6G-11 for NEOs, PFR5G-11 for S1s. Ive tried iridium, and they only lasted around 30k before they broke down. A set of splitfires would be a good investment as well.

if its in safe mode its in it for a reason..

running power fc? limiter set?

Running a boost controller? gain set at what?

Fuel pump on the way out?

How we going to help if you dont tell us wtf happened?

if you want to reset disconnect battery apply brakes for 3 or 4 pumps wait 10 mins then reconnect and restart. go for thrash, cruise and start stop movement..

Edited by DECIM8

none of the above, its been doing it since before it bought it. the guy replaced the plugs(probably the wrong ones), i havent had a chance to check yet. i just thought if i reset it i might actually be able to beat a a commodore off the line. im so disapointed in the slugishness of nisans. there should be no reason for it to lose to a straight 6 or v6. i would accept losing to a v8 but na 6s is sad

none of the above, its been doing it since before it bought it. the guy replaced the plugs(probably the wrong ones), i havent had a chance to check yet. i just thought if i reset it i might actually be able to beat a a commodore off the line. im so disapointed in the slugishness of nisans. there should be no reason for it to lose to a straight 6 or v6. i would accept losing to a v8 but na 6s is sad

Had the same issue with my brothers R34 4 door a before he sold it. Ordered some new coilpacks from Sliding Performance (in the trader section, cheapest in AUS).

Installed them and it was fixed...Of course i tried spark plugs first, but they just make it worse.... Coilpacks FTW.

ok it went away for a day or so and now its back. it also feels like the boost isnt increasing like it should. is it possible the ecu is running in safe mode?? how do i reset the ecu??

dude its 1 - your spark plugs or 2 - your coil packs.

had same prob with my 34 a while back - with me it was my spark plugs - had some iridium sh1ts in there... between 4000rpm to a bout 5500rpm it would splatter of its nuts.... and like you alot of the time would not get past 5000rpmm

I just put in some NGK's (neither iridiums or platinums, just normal plugs gapped right) - and prob fixed!!! smooth revs all the way to the limiter!!!! :D

and if you cant beat a holden 6..... something definitley wrong.... I can run faster thana crumbledoor!!! :(

Edited by FULOCK

nobody has suggested spark plug gapping as of yet have they?

if the problem seems to have occured right after a sparkplug change me thinks they are the cause?

oh and make sure he installed the correct heat rating- and make sure they are gapped correctly

could just be a case of gapping them down a bit and Viola!

Could well be an issue with the plugs.. My mate had plugs that were incorrectly gapped in his car, took it to get dynoed and it was missing up around the same rev range.. plugs were regapped and was perfect after that..

go out and buy (for under $19 total) NGK BCPR6E plugs. They are a 0.8mm pregapped, copper, v-groove plug. good for 300rwkw. if they dont fix the miss, you may need to buy new Splitfire coilpacks, or use industrial strength silicone sealant all around the current stock coilpacks.

give this a go first. should fix.

Another thing to check would be the fuel pump pressure. Mine was pumping at under 2bar (24-28lb) which meant that at normal driving it was fine (3000-4000 rpm) but try to push it and it would miss and carry on. A new sard fuel pump and all was back to normal.

The pump that failed was a walbrow it was only about 18 months old

Just something else to think about

Cheers

Phil

I was having the same problem. Started out minor last year some time and I just let it go. My fuel economy got worse, the idle got worse (espically on starting) and it got to the stage that any thing over half throttle and about 3000rpm it would shit itself. Today just installed a set of splitfires and new NGK Iridium (I've never had a problem with them at all). The car has never run this good since I've owned it. I'm back to running a 1.1mm gap (i've never been able to go higher than 0.8 but the old plugs were at 0.6) everthing from cold starting to idle and WOT are perfect. I'm keen to get it back on the dyno and tuned again now as when it was tuned last year you could see the break down of the coils badly on the chart about 4500rpm. upwards. Now I've remembered how shit the Auto's are in these things. Just as well I'll be recieving my MV shift kit this week :D

But I could also be your fuel pump too. Lucky this wasn't the case for me. But I'm still going to do it anyway soon just as a precaution and for further mods as its an 11 year old pump now and its probably going to be getting weak. I'm going to get a Tomei kit. They're more expensive but come as a complete kit with everything you need and no modifying.

Good luck with it. When you get it fixed you'll probably be surprised as to how much power the car has. I'd forgotten. :D :D

yeah- I am undecided about the irridium plugs in turbo cars-

I ran the irridium ones on my old SR20DE ( non turbo ) and the change was marked- but I didnt notice the same with a turbo car - thats why I tend to run coppers now - but must say I am curious about turbos and irridium plugs

It must be sed that I had already done the coil packs (split fire) and I replaced the plugs (platinum) as they looked a bit suss after running lean. I gaped the new plugs to .8 It was interesting to note the air flow of the standard plenum in that plugs 1 & 6 looked good and 2 to 5 were a light color witch would indicate more air flow in the middle of the plenum and less at either end.

If I have done it right there should be a couple of picks of the fuel pump

I ended up taking the whole cradle out only because I had not done this before

You need only grab the tab at the top of the fuel pump to release it from the cradle

Cheers

Phil

post-25786-1212657386_thumb.jpgpost-25786-1212657386_thumb.jpg

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

    • Hi guys, has anyone either purchased or built themselves a rotisserie for their car before? I can only just justify the need for one hence why I should just make one but at the same time, if I make one I can kiss another 4 weeks of potentially productive car working time goodbye because I'm building a bloody rotisserie....  I mainly want it for the application of the body deadener.  Cleaning the old stuff off, priming and then colour over the deadener doesn't worry me, it's just the application using the Schutz Gun that I feel would achieve a significantly better finish painting it side on and keeping the Schutz Gun upright.  I don't think they would work well on the side let alone almost upside down for some areas.  If the product I use (Terosun, etc) could work through a HVLP ok then it might be ok to apply without the rotisserie.   I can get one of these style ones for about $1200 which is pretty good value-     I reckon if I made one it would cost around $500 but it's more the time that it would take is more of a killer than the cost.  They look to hold their value pretty well second hand so I could always sell it after using it and realistically only lose $200-$300 at worst.  Or keep it and buy another project when this one finally sees the light of day... Anyone selling one...? Cheers!  
    • While it is a very nice idea to put card style AFMs into the charge pipe (post intercooler, obviously), the position of the AFM and the recirc valve relative to each other starts to become something that you really have to consider. The situation: The stock AFM is located upstream the turbo, and the recirc valve return is located between the AFM and the turbo inlet, aimed at the turbo inlet, so that it flows away from and not through the AFM. Thus, once metered air is not metered again, neither flowing forwards, or backwards, when vented out of the charge pipe. When you put the AFM between the turbo outlet and the TB, there is a volume of pressurised charge pipe upstream of the AFM and there is a volume of pressurised pipe downstream of the AFM. When the recirc valve opens and vents the charge pipe, air is going to flow from both ends of the charge pipe towards the recirc valve. If the recirc valve is in the stock location, then the section between it and the TB doesn't really matter here - you're not going to try to put the AFM in that piece of pipe. But the AFM will likely be somewhere between the intercooler and the recirc valve, So the entire charge pipe volume from that position (upstream of the AFM, back through the intercooler, to the turbo outlet) is going to flow through the AFM, get registered as combustion air, cause the ECU to fuel for it, but get dumped out of the recirc valve and you will end up with a typical BOV related rich spike. So ideally you want to put the AFM as close to the TB as possible (so, just upstream of the crossover pipe, assuming that the stock crossover is still in use, or, just before the TB if an FFP is being used) and locate the recirc valve at the turbo outlet. Recirc valve at the turbo outlet is the new normal for things like EFRs anyway. In the even of a recirc valve opening dumping all the air in the charge pipe, pretty much all of it is going to go backwards, from the TB to the recirc valve near the turbo outlet. But only a small portion of it (that between the TB and the AFM) will pass through the AFM, and it will pass through going backwards. The card style AFMs are somewhat more immune to reading flow that passes through them in reverse than older AFMs are, so you should absolutely minimise the rich pulse behaviour associated with the unavoidable outcome of having both a recirc valve and an AFM in the charge pipe.
    • Yep, in my case as soon as I started hearing weird noises I backed off the tension until it sounded normal again. Delicate balance between enough tension to avoid that cold start slip and too much damaging things.
    • I'm almost at a point where I feel like changing the alternator. Need to check the stuff you mentioned first though.
×
×
  • Create New...