Mysterious Pfc Missfire In An R32 Gtr

[itbmils]

I should have my car back this Friday and it will have a HKS CDI installed as well. Will see if the miss still occurs.

cool

I'd like to see what actually gets replaced with the CDI system - just to be sure that I have covered all bases

anyone know exactly what's in one of these kits ?

[steve_gts4]

cool

I'd like to see what actually gets replaced with the CDI system - just to be sure that I have covered all bases

anyone know exactly what's in one of these kits ?

i have one sitting on my desk infront of me right now...

it doesnt replace anything at all. you get a little bronze coloured box and a wiring harness (i purchased the BNR32 specific harness). the harness intercepts the TPS wiring to get power, and the wiring between the stock transistor pack and the coils.

i can post pics when i get home from work where my camera is.

[itbmils]

i have one sitting on my desk infront of me right now...

it doesnt replace anything at all. you get a little bronze coloured box and a wiring harness (i purchased the BNR32 specific harness). the harness intercepts the TPS wiring to get power, and the wiring between the stock transistor pack and the coils.

i can post pics when i get home from work where my camera is.

so

the std ingnitor (little silver thingy @ the back of the engine) is NOT get replaced

what about the std spark plug loom - does the new loom replace that or just plug into the existing one !!!

it provides BIGGER/FASTER spark - which is what my splitfire coils were supposed to be doing

[steve_gts4]

so

the std ingnitor (little silver thingy @ the back of the engine) is NOT get replaced

what about the std spark plug loom - does the new loom replace that or just plug into the existing one !!!

it provides BIGGER/FASTER spark - which is what my splitfire coils were supposed to be doing

all the stock looms and parts are still used.

[lwells]

Installation manuals for Twin Power are available here if you're interested: http://www.racecarnewmedia.co.uk/hks/installation.htm

[paulr33]

someone try with 02 feedback off like ash said

see if i helps

[itbmils]

Well guys

I think I have mode some progress here

I have moved the earth lead that comes off the ignitor pack.

I installed a grounding kit

I replaced my +ve and -ve battery terminals (with better quality units)

I did all this on Saturday (3 days ago) and so far - no more missfire

will let you know if it comes back

[paulr33]

still got good results ?

[itbmils]

still got good results ?

Well - funny you should ask

The car had been running fine - with NO missfire at all for the past couple of weeks

BUT

I had the guys at Mercury Motor sport do some work on the car early last week - and they removed the ignitor pack (to check the temp of my plugs) and when they put it back I suspect that they move the earth wire again

the up shot is that my missfire is now BACK !!!

I'll have a look at this again over the coming weekend and let you know if I fix it again

[Cubes]

Where did you move the earth wire to?

Just to give you something else to think about...

On the datalogit forums there's a brief mention regarding the pfc's Ign dwell vs RPM values.

It was noted that at low rpm the pfc defaults are too great causing the coils to over heat and run a tad too warm.

At high rpm 'apparently' they need a little beefing up. Nothing conclusive but something to look at.

It was mentioned that the splitfire coils require slightly different values to that of the genuine nissan coils.

The bloke doing the testing measured the values with some special tool designed to measure dwell vs rpm.

Well something along those lines anyway.

[itbmils]

Where did you move the earth wire to?

Just to give you something else to think about...

On the datalogit forums there's a brief mention regarding the pfc's Ign dwell vs RPM values.

It was noted that at low rpm the pfc defaults are too great causing the coils to over heat and run a tad too warm.

At high rpm 'apparently' they need a little beefing up. Nothing conclusive but something to look at.

It was mentioned that the splitfire coils require slightly different values to that of the genuine nissan coils.

The bloke doing the testing measured the values with some special tool designed to measure dwell vs rpm.

Well something along those lines anyway.

I installed a new engine cover (the bit in the middle that covers the coil packs) - this allowed me to move the ignitor pack back up on top of the engine cover. I took that opportunity to make sure I had a good earth when I moved it (which I assume the guys from Mercury have not)

Prior to having the engine cover on - the coils and the ignitor pack shared the same earth - and I was just using one of the screw holes that holds the coil pack (plug) leads in place

I plan to make a dedicated earth strap over to the -ve battery terminal over the weekend - so I will let you know how that goes.

Any idea how I would check my Ignition/dwell/RPM settings – can I check this with just the HC - I do not have any 'special tools'

I do run Splitfire coils BTW

[itbmils]

someone try with 02 feedback off like ash said

see if i helps

Also

my O2 feedback is already OFF

[PhilGTR]

Has anyone finally come up with a solution to this problem?? Since i installed my Power fc i been getting these stupid missfire also. Very very annoying!

[paulr33]

2 posts up

by scott

[itbmils]

2 posts up

by scott

yep

new earth for the ignitor pack fixes it for me

[paulr33]

updated powerfc faq with fix

[Cubes]

itbilmils,

I plan to make a dedicated earth strap over to the -ve battery terminal over the weekend - so I will let you know how that goes.

Was this what fixed it or was the std earths (with a nice clean surface) with the cover on sufficient?

[frankxinyu]

mine does this now...

i might have to try to relocate the earth for the ignitor....

does this miss do any damage?? my knock is normally below 15 any way, and the miss fire only happens once in a week or so...it only happens at cruising speed, and very light throttle...

[gtr fan]

Yeah the night my power fc went in mine started doing this. it has a great tune with minimal knock every now and then when driving off boost and making the transition to decent load I get a missfire but thats it then it just revs normally.

Like I said doesn't happen often and has not got any worse in 3 years.

[itbmils]

itbilmils,

Was this what fixed it or was the std earths (with a nice clean surface) with the cover on sufficient?

I think it just needs a good clean earth