Rb25neo Missing/acting Weird

[lilcrash]

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??

[chef_stagea]

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?

[chook]

yeah, start with fresh platinum plugs, prob never been changed....then move to coilpacks.

[KiwiRS4T]

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.

[wolverine]

perhaps a list of mods would be a good place to start.

(have you installed a boost controller)

[lilcrash]

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.

[chook]

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.

[lilcrash]

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??

[DECIM8]

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 June 3, 2008 by DECIM8

[lilcrash]

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

[sunnycoast]

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.

[Vik]

Yup same problem i had last week. Coilpacks did the trick and from Slide aswell.

MRXTCZ

[FULOCK]

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!!!!

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

Edited June 3, 2008 by FULOCK

[ssshonky]

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!

[SHIZNT]

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..

[Tangles]

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.

[STAGE1]

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

[Mr_RS4]

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

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

[ssshonky]

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

[STAGE1]

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