Skyline problem

[Chrisbown]

I have just bought an old-ish, 95, Nissan Skyline R33 GTS for some track day fun!
It has a missfire at 4.5k revs which only appears when the throttle is pressed hard. It does not happen when accelerated gently !
I have changed the plugs filters etc but this does not seem to help.
Any ideas ?

[EDLT]

I had a similar problem on a Rover and it turned out the rubber cap on the spark plug end of the HT lead was split. Although this only misfired at low revs and went away at higher revs but I still think its worth checking.

[cptsideways]

Duff coil packs, common fault only problem is finding which one it is! Suggest pulling an injector plug one at time, test until it disapears. Obviously you'll be on 5 cylinders but a misfire will make it only 4.

Easiest way to find the duffer/s

[liner33]

Coil packs are common best to switch to splitfires if you can but they cost around £250-£275 part number SF-DIS-001 for the series 1 engine and SF-DIS-005 for the series 2

There is a fix for them detailed on Skylineowners.com that may work for you

What plugs do you have

What boost are you running???

[The GMan]

You might have an airleak too?

I had a problem with mine before I sold it where it would miss underload then cut out. I replaced plugs, coilpacks and the afm also swapped the ecu. None of that fixed it. It turned out to be a dodgy ecu relay. They can be a pain in arse with issues like this but when they work they are a great car.

[cptsideways]

Theres also the option of going wasted spark, with an external coilpack system, check out driftworks for a rundown of the system, easy enough to wire up.

[Chrisbown]

Thanks for all of your suggestions, it's great to have the feedback.
Plugs are Iridium tipped and boost is standard.
Will try and isolate coil packs one by one and see if it helps.
Rgs
Chris.
Anyone know a good fixer, or garage, in the west midlands or worcestershire area ?

[Chauch]

Chris, my money would have been on plugs or coilpacks as well. http://www.mgt-racing.com/ are fairly local to you and Garth knows his way around Skylines very well.

[liner33]

Chrisbown said:

Thanks for all of your suggestions, it's great to have the feedback.
Plugs are Iridium tipped and boost is standard.
Will try and isolate coil packs one by one and see if it helps.
Rgs
Chris.
Anyone know a good fixer, or garage, in the west midlands or worcestershire area ?

what grade of plugs , they need to be ideally 7's or 8's

[tuttle]

Agree Sounds like coils to me,often a prob with these.
If you are happy using a multimeter there is a simple testing procedure for coil packs & AFM in the workshop manual.

Handy stuff in here

[_Batty_]

tuttle said:

Agree Sounds like coils to me,often a prob with these.
If you are happy using a multimeter there is a simple testing procedure for coil packs & AFM in the workshop manual.

Handy stuff in here

no plug for your shop?

[Chrisbown]

Hi,
What a fantastic response !
Thanks for all of your help especially 'tuttle' for sending the workshop manual over !
Can't see the 'simple testing procedure for coil packs & AFM in the workshop manual' yet but there are 500 pages to flick through.
I will find it soon I'm sure unless you know where roughly ?
Thanks again & will keep you informed when the new coil arrives.
Regards
Chris.

[Mooresy]

Just bought one myself. Just of the boat from the far east. hpoe I have no problems with mine.

[Bizzle]

99% sure it's an AFM problem.
If it was plugs or coilpacks your missfire would not be so predictable at 4.5k.

Swap it out for another AFM, see what happens.

[liner33]

These models of Skyline have a 2 stage boost the second stage coming in at 4500rpm , so thats when the most load is on the ignition system , thats why you get a misfire there

[Chrisbown]

Hi all,
Thank you very much for all of your help.
Got a coil & it appears to be the 5th one which is down.
Will keep you all informed of it's next problem, which no doubt will be self inflicted !
Thanks again
Chris.