Rb20det Minor Issues

[Quigga]

*********FINAL EDIT*****

been dynod at 119kw, it is definatly coilpacks, at full bost its blowing out the spark so by increasing boost it was just doing it faster!!! hope this helps people in the futre, will post up new dyno sheet when i get my spitfire coils

Heya guys i have a rb20det outa a r32 in my onevia, ive got basic mods FMIC with custom coolerpiping (vee port bov if that helps?), 3 inch highflow zaust, aftermarket fuel pressure reg (i think is the culprit), walbro pump and pod.

ive just finnished the conversion and i took it for a bit of a power run down the highway and i was boosting it felt fine, and when i got up around 5-6k revs (not sure tacho isnt wired yet) it would start to miss a little like it was ignition cutting. BUT if i put in the clutch and revd it i could go all the way to rev limiter no worries.....

Im thinking its fuel pressure reg cause ive never used one before, and it was already on the engine when i did the conversion. But i could be wrong, it idles fine and doesnt sound like theres any engine damage so its bizarre. I have an Apexi S-AFC which isnt wired yet but if its a fuel ratio issue i will

thanks quigga

*EDIT*

thinking it may be a boost issue, it only happens when boosting..... ive uped the boost and it only happens at full bost now?

prev i was running stock and it would do it at 8-9psi

now it does it at 13-14psi but not at 9

???? any more suggestions

Edited July 14, 2007 by Quigga

[blind_elk]

Heya guys i have a rb20det outa a r32 in my onevia, ive got basic mods FMIC with custom coolerpiping (vee port bov if that helps?), 3 inch highflow zaust, aftermarket fuel pressure reg (i think is the culprit), walbro pump and pod.

ive just finnished the conversion and i took it for a bit of a power run down the highway and i was boosting it felt fine, and when i got up around 5-6k revs (not sure tacho isnt wired yet)

How do you know if it's not connected. You might be hitting rev-limit.

it would start to miss a little like it was ignition cutting. BUT if i put in the clutch and revd it i could go all the way to rev limiter no worries.....

Im thinking its fuel pressure reg cause ive never used one before, and it was already on the engine when i did the conversion. But i could be wrong, it idles fine and doesnt sound like theres any engine damage so its bizarre. I have an Apexi S-AFC which isnt wired yet but if its a fuel ratio issue i will

thanks quigga

An engine will (generally) ALWAYS rev to red line with no load. (I once had an extremely clogged fuel filter that prevented the car going anywhere, but I could free-rev the engine until the cows came home!).

The consensus from numerous threads is that this is a misfire that will be cured by dropping the spark-plug gap down to around 0.8mm .

All EFI engines run a fuel pressure reg, so unless this is your first EFI car ... . Have you tried fitting a fuel pressure gauge to determine what's going on.

[1400r]

stock booost?

[Quigga]

ino its not limit because it wil stutter or watever and then go upto rev limit

cant be plug gaps i have iridiums(no gapping as the are preset)

havent put a fuel pressure gauge on just wondering about aftermarket fuel reg cause arent theyadjustable

yea stock boost

6-7 spiking to 9ish

[R32-PSH77]

I had the same problem on the highway.. i install iridiums and they sucks arse.. your most likely blowning out the spark cause the original coil packs are getting shagged.

iridiums are crap. your only advantage is that they last longer.. they will only work well if your runing some spitfire coil packs to help boost the spark as your 13 year old coil packs are probably heading for coil-pack heaven.

Mine are.. so until you can spare 600 bucks for some new coil packs.

This is from a previous thread read along if u like.

ust to share my experence

i have had a misfire problem since the day i bought the car.

started of bog stock, 10psi stnd everything it was running PRF5A11 so heat range 5 - 1.1mm gap

(misfired all over the place) worst feeling ever.

Changed to iridium BCPR6EIX-11 was good for few weeks, the along cam the exhuast and fmic

this raised boost to around 11psi.. and the misfire came back

changed fuel pump to a Bosch 023 largest internal Bosch pump u cant get. almost 300lph still misfire.. didn't change a thing.

Finally changed to some BPRC6ES (0.8mm gap with V grouve) ran 14.7psi (with new turbo ect) and No misfire

so the gap helped. i have actually done the high temp silicon trick to the coil packs.. worked a tad better.. deffintly the spark plugs that did the job.

however still awaiting a retune. so possible will all be running nice because 16psi+ shows slight misfire again.

Im going to get some splitfires.. but untill i save 600 bucks. im just going to run around with 24buck plugs. so i dont feel like im hitting a revlimiter from 2,000rpm to 7000rpm LOL

UPDATED.. i have had a Tune now. 12psi produces almost another 40kws that what i was making on 16psi. hardly any misfire at all.. however i was told to push out more boost i'd need to start looking at some new coils.

Hope this has helped

My 2cents

Adz

[blind_elk]

ino its not limit because it wil stutter or watever and then go upto rev limit

cant be plug gaps i have iridiums

Why not???

(no gapping as the are preset)

Gapped to "what?". Normally 1.1mm . Did you check them all?

havent put a fuel pressure gauge on just wondering about aftermarket fuel reg cause arent theyadjustable

All the more reason to put a gauge on it - how else do you work out what it's doing?

yea stock boost

6-7 spiking to 9ish

[zebra]

Vote #1 Plug Gaps

[TurboX]

There is no doubt that this is a great forum with a lot of knowlegeable skyline owners that can be helpfull when you have problems, BUT I seriously think in your case you should take your car to a workshop that has nissan RB experience!

Because its a conversion there are many areas that could be the problem and no-one on here can possibly take an overview of what you have and have not done in the conversion.

Every one will just be taking a stab in the dark with their own favourite theory and you will just be possibly wasting time without getting at the exact cause.

By all means take their advice, but get it to tuner who can definately ensure you are not just edgging it closer to a horrible demise by running it longer like it is trying to find the problem.

[Quigga]

thanks for all replys

ive changed plugs used 3 different types with all gapping specified, ive replaced fuel filter. Im very sure it could be coils not the plugs, as stated there old skool and it has been intermitant. Early in the morning when its REALLY cold i get no misfire, but during the day its haggard.

Electrial laws say add heat to electrics and efficentcy goes way down.

Im going to a good friend of mine and throw it on the dyno to see wat rpm its doing it and how the a/f ratio looks, hes gonna recheck the timing, test teh coils.

Ill keep everyone informed when i get results>>>>>

p.s feel free to offer more suggestions

Thanks Quigga

[cmfr32]

Definitly get it on the Dyno and check AFR's before you do damage. I had a similar problem when I upgraded my turbo, Tried gapping plugs, Elec taping the coils but no real difference. Upgraded the fuel pump (044) with rising rate fuel reg to richen it up and the miss under load disappeared. Ran it on the dyno as well watching AFR's to check it out. If its leaning out that maybe your cause. Don't get me wrong the coils could be your problem but a dyno run will certainly help find your problem.

[Quigga]

bump, update in first post

[1400r]

if your running the stock ecu with no remap fcd etc and it feels like someones turned off the motor when it cuts

I'd say your hitting the factory boost/air mass cut

normally happens at 13psi and above but on a cold night you can hit it a little earlier

due to spikes

so try running 12psi and see how you go

ps ditch the fuel reg its not need

[QWK32]

i use iridiums regapped to 0.8mm and don't have a problem

[Quigga]

if your running the stock ecu with no remap fcd etc and it feels like someones turned off the motor when it cuts

I'd say your hitting the factory boost/air mass cut

normally happens at 13psi and above but on a cold night you can hit it a little earlier

due to spikes

so try running 12psi and see how you go

ps ditch the fuel reg its not need

firstly it was doing it running 6-7 with 9 spikes, so its not factory airmass cut

why ditch the fuel reg? the point of it is to stop fuel surge and keep it at a consistant fuel pressure

[bubba]

Stock boost on an RB20 is 9-10psi anyway.. how is it running 6-7psi? sounds like there is some other problem present..

Also I'm not sure if RB20s have fuel cut.. I haven't managed to hit it on mine with 14psi through the stock turbo or 13psi through the RB25 turbo..

[mad082]

i'm pretty sure the rb20 ecu doesn't have rich and retard, so i doub it is that.

if you have changed the plugs it more than likely isn't them, but could still be your coils.

[1400r]

Heya guys i have a rb20det outa a r32 in my onevia, ive got basic mods FMIC with custom coolerpiping (vee port bov if that helps?), 3 inch highflow zaust, aftermarket fuel pressure reg (i think is the culprit), walbro pump and pod.

ive just finnished the conversion and i took it for a bit of a power run down the highway and i was boosting it felt fine, and when i got up around 5-6k revs (not sure tacho isnt wired yet) it would start to miss a little like it was ignition cutting. BUT if i put in the clutch and revd it i could go all the way to rev limiter no worries.....

Im thinking its fuel pressure reg cause ive never used one before, and it was already on the engine when i did the conversion. But i could be wrong, it idles fine and doesnt sound like theres any engine damage so its bizarre. I have an Apexi S-AFC which isnt wired yet but if its a fuel ratio issue i will

thanks quigga

*EDIT*

thinking it may be a boost issue, it only happens when boosting..... ive uped the boost and it only happens at full bost now?

prev i was running stock and it would do it at 8-9psi

now it does it at 13-14psi but not at 9

???? any more suggestions

^ you said this and what now its not running 13psi

[Quigga]

ITS COILS.... The boost is "blowing out" the spark on the plugs hence the cutting, it was dynod at 119kw with it doing this so ill post new dyno sheet when it is fixed with spitfire coilpacks

thanks for the suggestions guys

quigga