R33 Gts-t Intermittent Missfire

[MitchHarland]

hey guys ive had my S1.5 GTSt for a while now, around 6 months and since not long after i bought it there has been an intermittent missfire, doesnt seem to be caused by anything imparticular and nothing particular seems to stop it, sometimes even turning the car off then restarting doesnt help but it generally never lasts longer than 30 seconds and then stops. it only did it once at a track day and it had only done 1 lap, then ran fine all day, and does it maybe every 2nd day if i drive it around a lot

thanks

[Ben C34]

Cool.

[MitchHarland]

sorry i meant to ask if anyone had the same issue and what caused it but i thought that was implied, but you knew that right?

[Trex]

Cool.

Cool.

[Ben C34]

sorry i meant to ask if anyone had the same issue and what caused it but i thought that was implied, but you knew that right?

Is the history of your car and mods implied.

?

[Humbla]

Service,as in oil filters an fuel filters and spark plugs,done recently? :-)

[MitchHarland]

yes its been serviced just recently and plugs are probably 5000kms old, coilpacks are about 10,000kms old
and it doesnt have many mods, hence the mods list being left out, and hasnt been modified or changed at all from when it wasnt doing it

[hardsteppa]

probably the carbys...or afm is the next thing I would look at...following the air fuel spark rule.

[Kinks]

Getting kinda sick of the newbie bashing here on SAU. If you want a forum full of cynical arseholes I know another place that used to be good. Go there and shit on people rather than ruining this place too..

There are a few common things that go wrong with ignition systems in general. Coil packs - if you bought a cheap brand replacement they are known to have random failures. You need to buy good quality coil packs. Plugs - need to be gapped to 0.8mm in most cases unless your coil packs are really healthy. Coil pack loom - sits in the valley in the top of the engine and gets really hot and really brittle. 100 bucks or so for a new one, there's a connector at the back of the engine and the coil pack loom is swapped over really easy. But it's good to narrow down the problem before just throwing money at it.

Intermittent problems are a bitch to chase. At least if it's a consistent problem you can eliminate the cause. When it comes and goes, normally that sounds like something is making a poor connection. Check your coil packs and the coil pack loom plug at the back of the motor. Unplug each one and spray it with some electronic cleaning solvent (from Jaycar). Shake out the excess solvent and plug everything back together. If it does start misfiring, with the engine running pull out one coil pack plug at a time. When you find the plug that DOESN'T make the engine run worse then you've found the one that was already misfiring. Then it's just a process of elimination to see if it's a dodgy connector, a dodgy coil pack (swap coil packs between cylinders and see if the problem stays with the cylinder or follows the coil pack).

[MitchHarland]

thankyou kinks for a serious reply, its much appreciated and seems to be becoming a rare thing on this forum, a shame really

coming from an xr6t coil issues are nothing new to me, was the only problem i had with my ford but was unaware of some of the nissan ignition problems

over the weekend i pulled the valley cover off to have a look, i hadn't done so yet and was relying on receipts from the previous owner
i ended up changing the plugs, it had 1.1mm platinums in it and i replaced them with 0.8mm copper cores. i know these wont last long but it was purely a diagnostics purchase as i wasnt sure if it was the plugs or not, drove it quite a lot over the weekend and it seems to have fixed the problem finger crossed

also found the coils are yellow jackets, and from what ive managed to find they should be ok?

now to my newest problem, just before i did the plugs and that over the weekend i took it to work a few days and noticed when it was sitting idling it was hunting really badly (350rpm-1500rpm continuous fluctuation) and just as my luck would have it its another intermittent problem, seems to be fixed by a small tap of the throttle, was speaking to a mate today and he reckons his laurel had a similar issue and it was caused by a dodgy TPS, does this sound like i could be on the right track?

again thanks for your serious reply

[Trex]

Because I googled inter misfire rb25 and it came up with the causes and diys on how to fix it. That's why no one takes it seriously.

The same with the hunting idle. Short skim through google showed. afm, tps voltages, vac leak, aac.

To know the common problems with above parts just search for them. I know for a fact there are diys for each of them.

[hardsteppa]

There are a few common things that go wrong with ignition systems in general. Coil packs - if you bought a cheap brand replacement they are known to have random failures. You need to buy good quality coil packs. Plugs - need to be gapped to 0.8mm in most cases unless your coil packs are really healthy. Coil pack loom - sits in the valley in the top of the engine and gets really hot and really brittle. 100 bucks or so for a new one, there's a connector at the back of the engine and the coil pack loom is swapped over really easy. But it's good to narrow down the problem before just throwing money at it.

Intermittent problems are a bitch to chase. At least if it's a consistent problem you can eliminate the cause. When it comes and goes, normally that sounds like something is making a poor connection. Check your coil packs and the coil pack loom plug at the back of the motor. Unplug each one and spray it with some electronic cleaning solvent (from Jaycar). Shake out the excess solvent and plug everything back together. If it does start misfiring, with the engine running pull out one coil pack plug at a time. When you find the plug that DOESN'T make the engine run worse then you've found the one that was already misfiring. Then it's just a process of elimination to see if it's a dodgy connector, a dodgy coil pack (swap coil packs between cylinders and see if the problem stays with the cylinder or follows the coil pack).

this is good advice. Seriously. however it's also advice that has been posted a number of times and easily searchable, hence the smartass replies because the same basic questions are asked when they're already been covered.

Go there and shit on people rather than ruining this place too..

so where is this forum that has shitting on people, some obscure European IP address maybe...? do you have it handy?

and OP you're keen to work on your car which is awesome and you'll find people here happy to help, mixed with smartassness lol. Could be an intermittent sensor issue, you might want to buy the Ecutalk cable so you can troubleshoot all the sensors on a laptop, very handy tool to have, as well as setting idle, ign timing etc. you can download the Nissan workshop manual too if you haven't already, which will tell you the normal operation voltages of sensors.

[Kinks]

also found the coils are yellow jackets, and from what ive managed to find they should be ok?

They are "ok". Enough people have had a problem with them (myself included as of last week) that I can't recommend them any more. My most recent set appeared to be causing an intermittent misfire (12 months old), I have put splitfires in there now.

Because I googled inter misfire rb25 and it came up with the causes and diys on how to fix it. That's why no one takes it seriously.

So there's 2 ways of handling it. You can either be nice or be a douche. Being nice is replying with "check the stickied FAQ in this section, it sounds like a coil pack issue" - it takes 5 seconds. Or just don't say anything. Being a douche is replying with sarcasm or derision, that doesn't help anyone.

this is good advice. Seriously. however it's also advice that has been posted a number of times and easily searchable, hence the smartass replies because the same basic questions are asked when they're already been covered.

so where is this forum that has shitting on people, some obscure European IP address maybe...? do you have it handy?

and OP you're keen to work on your car which is awesome and you'll find people here happy to help, mixed with smartassness lol. Could be an intermittent sensor issue, you might want to buy the Ecutalk cable so you can troubleshoot all the sensors on a laptop, very handy tool to have, as well as setting idle, ign timing etc. you can download the Nissan workshop manual too if you haven't already, which will tell you the normal operation voltages of sensors.

It is searchable via google but SAU's search engine is pretty bad. Also, intermittent issues are a pain to diag hence asking for expertise. If you have a car that always misfires at WOT near peak torque then it's an open and shut case of coil packs or spark plug gap. Intermittent issues are a PITA.

If you want to shit on people visit Performance Forums. About 10-15 years ago it was a great place.

Good call on consult cable + ECUtalk. Being able to read fault codes off the stock ECU is fantastic. Although I don't think R33s throw a code for ignition system, my R34 certainly did (until I ripped out the stock ECU anwyay)

[Humbla]

I can vouch for splitfire quality, have a set in my ol girl for 11 years.:-)

[Trex]

Thread closed. Believe it or not, but since SAU started more than 7 years ago, this topic has been discussed before.

Please use the search function in future. It may be found here:

http://www.skylinesa...earch_in=forums

While we understand that it can be frustrating to have your thread closed - Please consider that other members may feel it to be disrespectful and selfish of you to post a simple question, without using the search feature to review the wealth of information provided by said members over the years.

[MitchHarland]

I think maybe before going around abusing people that are new to the forum you should work on your search feature, it's terrible and nowhere near to the standards of all of the previous ford forums I was a part of and many many other forums. Just a suggestion

Hmm may have to look into some splitfires if the problem returns or I was also doing a bit of research into LS1 coils possibly

[Trex]

I think maybe before going around abusing people that are new to the forum you should work on your search feature, it's terrible and nowhere near to the standards of all of the previous ford forums I was a part of and many many other forums. Just a suggestion

Hmm may have to look into some splitfires if the problem returns or I was also doing a bit of research into LS1 coils possibly

The sau search function works fine if used correctly, meaning correct spelling. You should have hundreds of threads detailing causes and fixes for your problems.

Typing in your thread title into the search function brought up said hundreds of threads. This was one of the hundreds on the first page. http://www.sau.com.au/forums/topic/326043-resolved-misfire-in-r34-gtt-rb25det-neo/?fromsearch=1 this thread details many of the causes of an inter misfire and the ways to fix it.

[MitchHarland]

the search feature from the mobile version of your site gave me about 15-20 results on the first page, 4 of them being about gym supplements? and a few others about missfires at high rpm, the first 5 pages have no information on anything similar to the problem i had
as you can see by the likes on my comment im not the only one who thinks the search is rubbish, and this is why i made my own post

isnt that what a forum is for?

[Kinks]

The sau search function works fine if used correctly, meaning correct spelling. You should have hundreds of threads detailing causes and fixes for your problems.

I've been on here 10 years longer than you have. Trust me, sometimes the search engine just spews random threads at you.

The more I think about it the more I think it's a dodgy connection somewhere. Most likely the main coil pack harness plug, one of the 6 coilpack plugs, or possibly something internal to the coilpack. Some electronics or contact cleaner spray might help it.

It's also worth reading off the fault codes. If you search (hah!) you should be able to find a thread on how to read the fault codes by bridging 2 pins on the consult connector and then reading the check engine light flashes. In case SAU search engine is being gay here's 1 guide:

http://www.sau.com.au/forums/topic/266512-reading-nissan-fault-codes-ecu-fault-codes-how-read-them/

Grabbing a consult cable and a free copy of ECUTalk is also recommended.

[Hadouken]

Seriously. No one uses sau search engine. Just use google. Much easier. Include sau in your search vuala.

I agree with both parties here however. And believe that moderators need to step up their game on this forum. Nismoid used to be on top of these repetitive threads hence why these "bashings" are occurring.

Just maybe try and google it before you start a thread. Then how about you say you have tried xxxxx and xxxxx didn't work.