Jump to content
SAU Community

Recommended Posts

Another problem has surfaced with the 32GTR now. A few days ago it wouldn’t start having sat for about 5 weeks and driven very rarely. As it turned out the plugs were fouled, and so were replaced. They were copper Bosch plugs, and were replaced with Iridium plugs (before anyone says they’re a waste of money, they cost 60 bucks).

The car has developed a misfire. It does it more or less across the rev range, when half to wide open throttle.

The new plugs are pre-gapped at 0.8mm. Modifications to the car are very minimal – turbo back exhaust with split dumps, removal of ‘boost restrictor’. Running Mobil 8000, Motul 300V.

Why is the car missing??? Boost cut? AFMs maxed out? I don’t get it! It is getting frustrating.

Thanks for any suggestions

Does it miss at idle?

On idle disconnect a coil pack, see if it makes a difference to the way the car idles and tbhen plug it back in. Do this one by one for all coils while the car is running. The coil you unplug and doesnt change the idle of the car is the stuffed one (if they're good when you unplug them it will start idling funny) :(

Hope thats it :(

Thanks Amaru, but it doesn't miss at idle. It doesn't do it continually either, seems to be an intermittent problem. May pull out the plugs again on Sat and see if they are clean or fouling.

Any other suggestions?

Have you taken it for a decent drive?

My car was in getting sprayed for around 3 weeks without being started.

When starting it was a real pig to get going almost sending my battery flat.

I had to keep the rev's above 2000rpm other wise it would die in the arse.

It ran really rough with a type of miss.

10-15km's later it began to smooth out and returned to normal.

It was a pain in the arse at the traffic lights :(

I was told it was a leaky injector. Who knows.. It runs fine now. :)

I do get the occasionaly slight wanting to stall every other morning.

Get it a flick of the throttle and rev's come up and the car runs fine, if I don't it will sit there lumping over until it stalls.

Okay, done about 250 kays since the panel shop, still using the iridiums.

We pulled out the plugs on Saturday, and all of them are perfect, no fouling.

The only time it misfires is when on boost, it idles fine, will happily rev out on partial throttle, however whenever under load it misses.

My feeling now is that it could be a number of things:

1. dodgy coil. Better plugs, maybe demand more from the coils, and hence only misfire under boost.

2. dodgy igniter? My guess however is that this would cause the car to misfire continually.

3. dirty AFMs. Would this cause misfire under load?

4. spark being blown out by boost. Iridium tips are very small, would the spark be too small and get blown out by boost?? I would have thought not, seeing that these plugs are only specified for GTRs and supercharged mercs :rofl:

I may have to go back to coppers and try that :)

hmm was just reading a thread RE surging... can someone define 'surging'

I wonder if what I describe as 'missing' is surging?

What I think of as 'missing' is when I floor it, the engine loses power, and just stutters but will still rev...

HELP!

I posted a thread about my car surging, and yes surging I mean missing. It runs perfect until I boost it anymore then about 9psi then I starts to shutter like a dog. I'm going to check the plugs tonight and regap them to 0.8 and check the coils for any cracks.

I thought my last original coil pack died the other day, displayed the same symptoms you’re describing…this time it wasn’t the pack that had died, it was the connector on the loom. Just pushing slightly on it was enough for the missing to stop!!! I cut it off and replaced the spade terminals, and now it works fine.

It was very intermittent as the connector expanded on heating making the terminals…break contact now and again.

Does anyone think that the Iridium plug electrodes are too small and the spark is blowing out on boost? B/c the copper electrodes are a dirty big lump of copper...

Will switch back to copper this weekend and see if that works

Hey i have seen this with the iridum plugs a number of times having replaced them with NGK bcp6es or 7es tends to solve the problem but if it continues try the spring conection between the coil and spark plug as corosion can build up and cause a problem.Good luck

Hey i have seen this with the iridum plugs a number of times having replaced them with NGK bcp6es or 7es tends to solve the problem but  if it continues try the  spring conection between the coil and spark plug as corosion can build up and cause a problem.Good luck

Thanks GTS500, will give it a shot.

I have a feeling it may be coils on the way out too.

  • 2 weeks later...

For those of you who care, I installed a set of DI Splitfire coils tonight. Seems to have solved the problem, but still misses a tiny bit high up.

Might have fouled plugs driving around with dodgy coils for 2 weeks (too lazy to pull them out tonight and check), but will try some coppers on Sat - should be tip top by then.

  • 8 months later...

I am currentlly having this problem... I put in iridium's last night and what do you know. Everything over 8-9psi it misses like a littch beatch....

How do you guys go... I used 5's as their a colder plug and worked really well in my old rb20 powered line.

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

    • Waaay ahead of ya....(evil laugh!!) Will show the fitment and spec details later when it isnt as rainy !
    • Thanks Dose.....    I appreciate it!!
    • I'll probably be putting the shit box back on the dyno again soon, I want to dial in the closed loop boost control properly. I'll have a camera facing the car/motor for fun too. Just note, there are essentially 3x 10AN inlets going into the catch can and 1x going back to the intake pipe. Most of the time the catch can "return" to the sump actually is the crank case breather, pushing air out.
    • I have the R3C with a Nismo slave and by no means does it behave like a stocker, it ain’t THAT bad. On take off just give a bit more throttle than you would say a coppermix and it’s fine. It will not slip though.   
    • Okay. Final round of testing done. Got a friend to hook up a fancy scanner to the car and we also ran some compression and leakdown tests, she is healthy.  The MAF was definitely the culprit. So for future reference anyone with similar issues that find this thread. I suggest the following steps, in order of affordability:   Check your spark plugs for any fouling, replace plugs if they are bad or re adjust the gaps making it narrower (0.8mm would be good). Check every coil's resistance with a multimeter. It can be done by probing the IB and G pins on the coil pack. Resistance should be around 1.4 (+/- 0.1) Ohms Check the MAF. If you have Nissan connect or a good scanner with the 14 adapter it should allow you to see the voltage on the MAF reading should be around 1.1 - 1.2V when car is idling. But if you don't, buy a new MAF from Amazon and test, then return it. (For instance, I got a Chinese one for $40 that was reporting 1.3v on idle). If you still have scanner, you can run tests on the injectors to see if they are working, just remember to unplug the fuel pump fuse/relay and have no pressure on the line. Then listen for the noises that the injectors make. Clean/replace injectors as needed. Once you find the issue and fix, order thousands of dollars worth of OEM parts to refresh unrelated things (Optional)   PS: Thanks to the absolute legends of this forum for the responses and help to someone that went a bit over their head. (me)
×
×
  • Create New...