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So ive got a 98 Non turbo R34, i had one coil pack go a few months back and replaced it, since replacing it i noticed when i started my car occasionally it would die unless i keep some revs on it for the first few seconds and would usually stay jumpy around 700 instead of steady on 1k revs . i thought this could be the spark plugs or other coil packs because im just under 100,000 k's so i went and got a set of 6 coil packs that were off a low k's 34 in perfect working order and some new nismo spark plugs 0.8 heat range 7. fitted them all, noticed a vacuum purge in one of the rubber grommet seals on my rocker cover fixed that and put everything back together but problem still there. i just replaced the O2 sensor a couple months back so last thing i could think of was the fuel pump, got a new one fitted and same problem and now i also have an occasional put put sound that comes through the exhaust. sounds like the timing of the engine is off

and now im out of ideas on how to get it running mint again

i have a video of the car struggling to start

http://www.youtube.com/watch?v=pvNUk18iGX4&feature=c4-overview&list=UULMTc8BU-SPQo_YbXqXHwpg

and a video of the put put sound, its kind of hard to notice it through the recording

http://www.youtube.com/watch?v=1c31tleK8GM

has anyone gone thought this or have any ideas on what else it could be

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the put put tends to happen mostly when its cold, but the struggle for ignition happens when ever i have to start the car, once i start driving it feels almost normal besides the occasional slight put put that goes through the exhaust. i haven't driven it much since these problems have come up just been taking it from mechanic to auto electrician

Get six BCPR6ES spark plugs (they are like $3 each), gap them to 0.8mm (they should already be 0.8mm so check the gap), put them on and see how the car runs. Sounds like failing coilpacks unfortunately. Could be the other ones starting to die.

I put yellowjackets on my R32 GT-R, the slight miss on idle is gone and revs noticeably better. I use 1.1mm plugs now as well (better spark, BCPR6ES-11).

ok ill grab six BCPR6ES spark plugs tomorrow and chuck them in as well as put the original 5 working coil packs from factory + the 1 i bought to replace the the first dead coilpack (bough from nisswreck and confirmed working by my mechanic) and see how it runs then,

does it matter if you run cheap spark plugs? or does it just mean youll be replacing them more often?

and with the new spark plugs i guess i should get heat range 6 too?

thanks for the help

ok so i did as said above and it solved those two main problems perfectly! thanks so much for that!

although there is still the slight loss in rpm when in neutral and i slowly rev, the revs will increase as usual but then will drop off slightly. it only happens around 1,800 rpm as far as i can tell

heres a video that shows it happening, you may need to turn your sound up yo hear it

http://www.youtube.com/watch?v=i81v3nyLurY&feature=youtu.be

anyone have any ideas on why this would happen? maybe something to do with the aftermarket uprated fuel pump?

The copper spark plugs won't last as long as the more expensive ones, but they're so cheap I wouldn't mind replacing them every 10k-15k km.

It sounds like you're running factory coils, they're 10+ years old now and wouldn't be working as awesomely as new ones. You can always get new Yellowjacket coils for a very good price. Even if your old coils are working "fine", new ones make a difference (well they did on my car, but mine is turbo).

I can't watch the video loud (at work), but if it's running smoother than before, maybe just drive around for a bit until you can replace the coil packs.


Also, why would you need an aftermarket uprated fuel pump for an N/A?

yep thats probably what im going to do, i found brand new factory ones for only 250 so thats a cheap option as well

i dont need and didnt really want an uprated fuel pump, but it was $ 50 cheaper that a stock replacement and was going to be 2 weeks faster postage so i just went ahead and got it

The copper spark plugs won't last as long as the more expensive ones, but they're so cheap I wouldn't mind replacing them every 10k-15k km.

In a NA they last pretty long. I changed the copper plugs in my Commodore after about 50,000kms only because I was chasing a misfire (which new plugs didn't fix).

^ True, I replace the ones in my R31 every two years lol.

As for those cheap coilpacks, they are fake (there's a post in here somewhere that shows the difference). Hopefully they a few years so it's not a complete waste.

  • 2 months later...

i ended up getting new yellow jacket coil packs and put in new spark plugs also, but my revs are still unsteady and i can feel power dropping in and out when i slowly put my foot down basically im out of ideas as to what it could be, any more suggestions before i get my wallet raped by a mechanic

Lets look at this logically for a second.

We have ruled out spark - new coils and plugs mean it cannot be them.

I wouldn't go so far as to say fuel could be the issue, as it is not at high RPM range.

Maybe the AFM? I would say it is a tune/ecm related issue. I'm not sure how AI based the computer is - I mean does it change the tune depending on how the motor is running? I only say this because I had a friend who dropped a 25neo into his 32, it ran like crap for a week - spluttering, maxing boost at 4psi, etc. As it was his only car he kept driving it. Then one day something just clicked - boom - perfect tune and 12psi.

What I am getting at is maybe because you were running f**ked coils and plug for a while, the computer has compensated and is now giving you this flat spot - maybe running rich/lean. I'm not saying run it and see, but maybe hooking a computer up to the ECM may yield some results, and may just need a flash.

im pretty sure i can rule out the AFM, i checked it and got a mate whos a mechanic to check it again for me,

but the computer trying to compensate sounds like something it could be

since ive changed the spark plugs and coilpacks ive only done around 100 km's the first drive was fairly smooth, second drive i could tell straight away the problem was still there and then the most recent drive was the worst, i cant cruse in any gear but 5th above 3k revs with out the revs jumping and that was when i could notice the power dropping in and out as i would accelerate. the issue definitely seems worse when the car is cold.

but yeah i will get it into my mechanics asap and see if they can get anything out of their computer and ill see if they can reflash it

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