Rb25Det Missfire Pls Help Tryed Lots

[Skline1993]

hey iv recently bought a r33 series 1 mods

Apexi power fc

front mount cooler

z32 afm (new)

yellow jacket coil packs (new)

new plugs iridium ngk heat range 7 already gapped to .8

new fuel filter

Ok so i bought this car recently went great when i got it was unrego so i decided to service it before putting it on the road i put some new spark plugs in same as what came out of it with new fuel filter cleaned maf and put a full tank of 98 in it ever since the car hasnt been boosting properly slight hissing sound checked for vaccumm and boost leaks none i can hear a slight whine on boost only seems like a air valve is stuck open???Has knock readings on hand controller goes well cold then warms up gets worse has bad fuel economy can ease on boot without knockin bad but if plant it goes nuts poping not sudden jerking just lack of power when warm and backfiring when try to limit usually change gear before boost 2nd stage

Things iv tryed

Checked for boost and vacc leaks

Replaced spark plugs

Changed oil and oil filter

Repalced MAF

Replaced coilpacks yellow jackets

Cleaned iac valve

New Fuel filter

tryed different tank of fuel incase bad fuel

[Ben C34]

Did you pressure test when looking for the leaks?

If you didn't you need to.

Did the car ever run right? Does it need to be tuned?

[jiffo]

What is the boost reading?

Think you may have mixed up the actuator pipework and you're getting excessive boost.

[V28VX37]

If it's breaking down at higher RPMs, check your CAS. That's what caused my severe misfire: http://www.skylinesaustralia.com/forums/topic/326043-resolved-misfire-in-r34-gtt-rb25det-neo/

[blind_elk]

Factory heat range for spark plugs is "5". Unless you are making serious power, you shouldn't be using "7"s.

Have you cleaned the injectors (remove and sonic clean, not a just bottle of cleaner)?

[Ben C34]

Ok I reread your first post.

It went great when you got it. So that means something you did made it run shit.

It could be the coil pack loom as they get old and brittle and don't like to be jiggle.

What boost are you running?

[Skline1993]

its running very rich 300km to a tank iv try'd all the heat ranges from 5-7 with the spark plugs

only just had the timing belt done was missfiring before i had timing done

i rang my tuner he said maybe cat converter?

randomly has power then others just nothing but slugish its running 12psi

Sometimes i feel a small surge of when its going in and out of power then 10 minutes later will be shit again goes well cold

i also found one day it felt like i was pushing the throttle in was very stiff like i was pressing against the psi in the motor or somthing wierd hasnt done that for a while dont know (bov may have been sticky didnt drive for a while?? stoped the car pedal went soft again wtf? lol

the exhaust does stink how can i check my cat

when the knock sensor stays flatline it goes good instead of slowly creeping up the graph the more i throttle it on the power fc no power after 4k rpm

(Thanks alot for the replys!!!) first time posting really apreciate the help

[Skline1993]

Seems air related ? like some valve my ac busted one day could have stuck a air valve open?? i dont know just stuck for ideas lol

Edited July 6, 2014 by Skline1993

[Lrs94]

the exhaust does stink how can i check my cat

If it smells like rotten eggs that is a sign on a bad cat, you can try tapping it and seeing if it sounds hollow or if it sound solid. take it for a drive so your car is nice and hot and measure the temp on each side of your cat, should be roughly same temp.

But I am with Ben on this one, pressure test your system, I was having a lot of problems and I never bothered to pressure test because I didn't think I had any leaks as I still saw 7 psi on boost gauge, decided to test it as I ran out of ideas and turned out a weld along the side of my Intercooler was split. Car run like new now haha

[Skline1993]

i didnt do a pressure test but it seems to boost fine when it wants to seems sensor related :S i can hear the note change and torque straight away when it decides to go normal for few minutes

[Skline1993]

i opened my oil cap after changing the oil stunk really bad like eggs????

Edited July 6, 2014 by Skline1993

[Skline1993]

knock sensor creeps even on idle

not when cold though just stays nice and flat once warm it goes up and down slightly

im no good at explaining but when the thing stays flat its fine sometimes just decides to stick around 20 on cruise and feel like a slug

[Skline1993]

will do pressure test and get back to you thanks and try tapping on the cat

Edited July 6, 2014 by Skline1993

[Lrs94]

i didnt do a pressure test but it seems to boost fine when it wants to seems sensor related :S i can hear the note change and torque straight away when it decides to go normal for few minutes

Boost leak will affect sensors as well, your intake sytem may have a leak, so your turbo is working extra hard and pushing large amounts of air through your system, but not all the air your turbo is pushing out is getting to your engine, which means your air flow meter will be giving false air measurements to your ecu, and this will give you a bad air/fuel mixture depending on how bad the leak is, and may cause your car to run like shit.

[Skline1993]

so ive had my swap done now for about 2 months into s13(bought from a friend was running and driving with no problems). put it in got it running, ran like crap knock sensor was unplugget and I put new plugs in, fixed ran awesome. the biggest plug gap I can run is .026 or it cuts out maybe that normal but that seems kinda small to me coming from sr to 1j and now rb(should have stuck the 1j). that was an sc300 though. anyways my car kept going into limp mode like I had a bad maf and it would fix itself on its own, it never does that anymore though.

now after it warms up it has vary noticeable power loss and it even sounds different, like its pulling timing or something.
things I have done
was throwing code 13 got a new coolant temp sensor didn't change
checked voltage at ecu for knock sensors they were both 2.5v at idle
set tps and made sure it was correct when set while wot and closed
boost leaked checked multiple times and its solid
haven't messed with bov still recirc
tried 2 different fpr's and new z32 fuel filter
put extra grounds from block to chassi and an extra ground on coil pack harness
checked voltage at fuel pump 12 volts
when I put the motor in the timing was set at 20 degrees according to how you look at it rb's its kinda weird depending on the angle you look at while timing it. it had been that way for a few years with no problems im timing by putting my timing light on the white wire at number 1 coil with the timing light hooked up to a jump box for power because my battery is in the trunk. maybe that's all no good and need to make a wire from the coil to the spark plug and use that to time it?

now after about a week it throws coolant temp code again, so I ohm the wiring between sensor and ecu and I doesn't say offline but it reeds o.o ohms. I check the ground and its 3. something.

info about the swap
s1 rb25 mostly stock
I think its an older wiring specialties harness but its a little old now
hks actuator set to 9 psi
n1 thermostat
walbro
pulled from my friends running s13 and about 3 weeks later running in mine
pumped all old gas out of my shell and put new premium in
cx racing front mount
3 inch dp and exhaust

I don't mean to ramble on to run so good and strong sounds good while its warming up, and I don't mean dead cold and romp on it I wait till needle starts to rise on temp and pulls hard all the way to redline, then temp gets halfway up and gets slower and slower till it sounds way different and feels like has no boost just a na motor, still drives smooth though doesn't cut out and super rich. I don't have a wideband but it uses tons of fuel and backfires a little usually when I take my foot off the gas and start coasting.

ive tried everything I can think of and before I rewire my coolant temp sensor to the ecu I figured I would ask. ive b

[Skline1993]

very simular to this thread i found a small leak but still runs like shit iv got a new coolant temp sensor yet to install could the old one be reading wrong and causing these symptoms

[Skline1993]

checked my power fc water temp after letting it idle for 5 minutes took for a 5 minute drive says 98c is this to hot??

Edited July 9, 2014 by Skline1993

[Lrs94]

That's is normal temp, I wouldn't worry mine sits about 102 degrees according to nistune