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Hey all.

Ive got a 94 gts-t, if I try boosting it over 10-11psi it starts to missfire in a pretty harsh way...

Anyway I took it to Gavinwoods autotech (some of u qld'ers may know him) and he came to the conclusion its a problem with the coil pack. I cant remember now wether he said it was just 1 coil, or the whole lot needed replacing. anyway he ended up changing the plugs and setting the gap etc on em, and didnt really want much more to do with it.

My question who/how can test which one it is, and is it ok to just replace the 1 faulty coil? i was told coils are around $200 EACH! new from nissan (which I aint planning on paying that much) or around $90 if im lucky enough to find them second hand.

The next mod im looking at is a new ballbearing turbo, so I would like to get this sorted before I purchase a turbo and am stuck with 10psi instead of 18 or so :)

and I have a fmic along with other mods so it can handle 10+ psi easily...

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https://www.sau.com.au/forums/topic/14075-coil-pack-problems-on-my-r33/
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try searching these forums first...

it is a common problem with R33's because of the ignition maps on the standard ECU. I seriously doubt it is one of your coil packs, as it would always happen, not just when you boost past 10psi.

Only cures I know of are:

- Aftermarket ECU

- Piggyback ITC for ECU

- Advance timing past 20 degrees (although could be dangerous)

Exactly right...its the spark plugs, get some .7mm gapped plugs...my friend spent BIG $$$ and it ended up being the plugs, its like Popping sound with more than 11psi. He changed plugs and now its gone...

Get some good platniums or iridium IRIWAY, pm me if ur want heat range 7,8,9 or 10 (true racing plugs, which no one will stock, except performance places. about $28.00 each but more than perfect and last 80-150,000km)

what kinda power figures r u looking at?

A heat range of 8 seems very cold to me.

Let me put it this way, I have a turbo back xorst, filter, and boost controller (set to 11psi), and I am using a heat range of 5!

I was using 7, and they would foul very quickly, and within 2 weeks of installing/cleaning, the problem would return.

I used 6, and it was much better, but still happened if I didnt thrash it once in a while.

I am using 5 now, and initially it was much better, the car was purring like a kitten, but if I have been giving it heaps, I notice a little pinging.

So a heat rating of 8, is overkill with only basic mods, and only makes your problem worse. (assuming you only have basic mods that is)

And, go the coppers next time, they produce a better spark, but dont last as long.

NGK BCPR6E is the best plug I've used so far (and yes I have used platinum plugs too)

Do a search, I'm sure some people are really sick of me talking about spark plugs :D, as this has been brought up before lots of times, you will find some other useful info too.

George

Well most of us have had this problem, and the way I solved it was:

- NGK BCPR(5/6)E plugs at 0.7 mm (better 6)

- take car for 15 min drive to warm it up

- Reset ECU

- advance timing to 20-23 degrees (careful though this is done properly to avoid pinging)

- Take car for a good thrashing (if it pings, then re-do your timing - retard it)

My car has the same problem. It is setting at 0.7bar now. Anything more than that will have popping sound/ misfire.

I have already re-gap my spark plugs to 0.8mm from 1.1mm. And they are platinum plugs. (before re-gap them, I can't boost anything over 0.5bar (stock boost I think)

Will the after-market computer solve this problem. I want to boost it to 0.8 or 0.85 bar and should get better fuel economy by the new computer.

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