missing at any thing above 0 boost.

hozza

Leaving Skid Marks
Location
Queensland
First Name
Nathan
Drive
97 COTY manual legnum.(gone)
96 GTO MR
S13 silvia
There are a few threads out there about there car missing but none of them are the same as what my legnum is doing.
It revs smoothly all the way to 7000rpm if i climb gradually.
as soon as the boost hits much above atmosphere the car starts missing.
this happens from about 4000rpm on.
I am currently running ice leads with BKR7EIX.
They were gaped to .8mm by previous owner today i regaped them to .7mm
while servicing and applying dielectric grease to the coils.
If any thing this made it worse?
I have tried servicing coil packs, ecu reset, cheaked for boost leaks and any other hoses that are split.
My only thought is that the low resistance of the ice leads is causing some issues with the spark?
Any help would be appreciated.
thanks
 

yoshimitsu9

Leaving Skid Marks
Location
victoria
First Name
stefan
Drive
ae86 sprinter
my guess is your plugs are fucked. i had BKR7EIX's in my car and they lasted about 12,000km

i know its like $140 but cop it on the chin and buy NGK's
 

twisted32

Leaving Skid Marks
Lifetime Member
Location
Adelaide
First Name
Rob
Drive
2000 Type S Leggy (toy)
NW Pajero (daily)
Try a set of cheap copper bkr7e plugs at 0.8mm. Re gapping irridiums can damage them. I had issues with my iridium 7's (15k old) also with ice leads, coil pack service etc, and was sure it was not the plugs. It would only miss at WOT, not at 90%. Guess what, it was.....
If the new coppers don't make a difference, try replacing one coil pack at a time to eliminate each one (assuming you can borrow a known serv item from someone).
If the plugs fix it, just order some denso tough or ngk laser series plugs (both electrode and ground are iridium and or platinum compared with the cheaper iridium IX's) and replace in another 3-4k when it starts again.
 

unclepaulie

hellatemplate ;)
Lifetime Member
Location
QLD
First Name
Paul
Drive
hairdresser spec lancer coupe
or buy COP and watch your plugs last upwards of 20,000 on 17psi
 

hozza

Leaving Skid Marks
Location
Queensland
First Name
Nathan
Drive
97 COTY manual legnum.(gone)
96 GTO MR
S13 silvia
Ill try some copper ones see how they go.
I hope they cop rolling group buy go's for a while.
really need to start saving.
 

naughtika

OzVR4 Stalker
Location
Brisbane, QLD
First Name
Christian
Drive
'96 Galant VR4, '17 MB A180, '25 Macan GTS
BKR7EIX only last for 40k kms on stock turbo cars.. so if you have your boost turned up.. you'll be lucky if you can pull 35k kms out of it..
 

Worridge

Leaving Skid Marks
Location
Somewhere
First Name
Don't worry
Drive
98 Legnum AKA KEN
If its any relevance, I ran irridiums for a while on my 2 stroke motocross bike and found they would only last one ride. The spark area on them was tiny so as soon as a speckle of carbon fell on them they would oil and not hold high revs. Not sure about the car ones though.
 

naughtika

OzVR4 Stalker
Location
Brisbane, QLD
First Name
Christian
Drive
'96 Galant VR4, '17 MB A180, '25 Macan GTS
If its any relevance, I ran irridiums for a while on my 2 stroke motocross bike and found they would only last one ride. The spark area on them was tiny so as soon as a speckle of carbon fell on them they would oil and not hold high revs. Not sure about the car ones though.

did you use the recommended model for the bike? also was there any modification done to it?
 

hozza

Leaving Skid Marks
Location
Queensland
First Name
Nathan
Drive
97 COTY manual legnum.(gone)
96 GTO MR
S13 silvia
35k these would have a max of 5k on them.
 

Worridge

Leaving Skid Marks
Location
Somewhere
First Name
Don't worry
Drive
98 Legnum AKA KEN
did you use the recommended model for the bike? also was there any modification done to it?

Yeah it was recommended by the shop for what I was running i.e jets, pipe, reeds etc. I was using the racing oil (the stuff that smells really good) but it just got too expensive to go riding. Consumables being oil, petrol and plugs. I ended up reverting to cheaper/warmer plugs.
 

TME_Steve

3 AYC Bars
Lifetime Member
Location
NSW
First Name
Steve
Drive
2010 nt did pajero tow car / 2000 6spd gc8 wrx tarmac rally car / 2000 Manual Subaru Outback 2.5 just a car
my first 7's lasted me 15k.... I could only run about 12psi, are you sure it's only when you cross to positive pressure, if so how about a boost leak, a leak that is sealed under vacuum but opens up under boost, like say a pipe disconnected? Just a thought.

But yeah regapping iridiums is dangerous, but from what I've seen they last better than anything else.
 

hozza

Leaving Skid Marks
Location
Queensland
First Name
Nathan
Drive
97 COTY manual legnum.(gone)
96 GTO MR
S13 silvia
yeah all my pipes are the silcon ones from ivan. and like 2 months old but could be on the silicon join to the intercooler.
ill try the plugs then look deeper into leeks.
not sure if it related but my car only idles at -10psi.
not sure whats happening with that.
 

twisted32

Leaving Skid Marks
Lifetime Member
Location
Adelaide
First Name
Rob
Drive
2000 Type S Leggy (toy)
NW Pajero (daily)
yeah all my pipes are the silcon ones from ivan. and like 2 months old but could be on the silicon join to the intercooler.
ill try the plugs then look deeper into leeks.
not sure if it related but my car only idles at -10psi.
not sure whats happening with that.

Well with that info (assuming you mean 10 inches mercury), I would definately be looking at pressure testing your pipe work, as it should be 18-20 in Hg at warm idle.
 

TME_Steve

3 AYC Bars
Lifetime Member
Location
NSW
First Name
Steve
Drive
2010 nt did pajero tow car / 2000 6spd gc8 wrx tarmac rally car / 2000 Manual Subaru Outback 2.5 just a car
-10psi would be good, -10 inches mercury would be bad what units does your gauge read in vacuum, most are mercury.

I would have thought it would idle crappy and run badly at low load at though at that point, anyway, sounds like a pressure test in order. Hmmm slippery silicon fitted only 2 months ago, methinks a pipe has come off recently
 

hozza

Leaving Skid Marks
Location
Queensland
First Name
Nathan
Drive
97 COTY manual legnum.(gone)
96 GTO MR
S13 silvia
its a digital gauge that reads -10psi. you may have just solved that problem.
Ive asked several mechanics they just keep telling me i have a boost leak.
cheers one less thing to worry about.
 

TME_Steve

3 AYC Bars
Lifetime Member
Location
NSW
First Name
Steve
Drive
2010 nt did pajero tow car / 2000 6spd gc8 wrx tarmac rally car / 2000 Manual Subaru Outback 2.5 just a car
My eboost 2 reads in mm hg for vacuum and psi for positive, it's digital too....
 

hozza

Leaving Skid Marks
Location
Queensland
First Name
Nathan
Drive
97 COTY manual legnum.(gone)
96 GTO MR
S13 silvia
yeah i might grab my mates mechanical gauge and put it on at idle just to check.
 

hozza

Leaving Skid Marks
Location
Queensland
First Name
Nathan
Drive
97 COTY manual legnum.(gone)
96 GTO MR
S13 silvia
Ok i changed the plugs to some copper bkr7e gaped at .8mm).
still no difference but it changed it makes it start missing at 4000 now :(
So i reakon maybe the leads?
Any one got a stock pair i can buy or borrow?
in the end might just be easier going cop.
 
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