R34 Gtt Issues...

[camoo]

Hey all,

So i have an r34 gtt.

Z32 AFM, Xspurts 725cc injectors, bosch o44 fuel pump, Nistune.

Turbo, cooler, exhaust bla bla bla.

Problem is cold start is shit, idle is a little rough, and one the cars warms up, it has quite a nasty stumble low in the revs under slight load.

Everything else is great, just gets annoying when cruising around.

AFM is good, no vacuum leaks, no apparent leaks.

Ive had it retuend multiple times, and cant seem to shake it...

Im thinking injectors, but i wanna know what others may think before i rip them out and replace them,

All my parts are less than 12 months old, and its driving me nuts.

Any help would be awsome.

Cheers, Cam

[Madaz]

have you got a blocked off BOV ??

when you block the BOV off it will fall over if you stop abruptly

as for the cold start and rough idle that i would say is tuner

[camoo]

na its a return bov, n it dosnt stall when i stop, just stumbles as i take off.

Ive been to 3 different tuners and none of them could sort it out.

[pistol-pete]

the stumble at low revs as you put it sounds like it could be coilpack related. but where have you been taking the car? coz the issues sound tune related to me.

or maybe fuel pump is on the way out

[Madaz]

a return bov can still have a blocking plate but since you say its on take off that rules that out

could be coil packs breaking down and when they're cool they're ok but when they heat up you have problems

[Jap_star]

mines been blocked for nearly 18 months steve and no issues here with bov

[Madaz]

i don't have issues either because i don't speed up to a stop sign or red light and jam on the brakes

some people do however have aggressive braking patterns

[camoo]

Brand new splitfire coil packs... So id hope it's not that... And the fuel pump has done barely 10,000 km.

I've been to garage 7, jaustech, and jazmac. Jazmac has put in alot of effort tuning,

[DC_GTST]

tried the ignitor for the coils? Was the case in mine recently - also have Splitfire's.

[Jap_star]

i don't have issues either because i don't speed up to a stop sign or red light and jam on the brakes

some people do however have aggressive braking patterns

is this steve?

[Madaz]

going fast and stopping fast are too different things

and i don't drive that fast like i used to either... remember all eyes are on Steve when I'm out and about

Dan - the R34 wouldn't have an igniter they are built into the coil packs since S2 RB25

[Carbon 34]

Its the ilde air control on the back of the manifold is carbon caked that controls idle air and cold start driveability

backside of throttle plate is most likely as well , check the TPS its a touchy bastard with nistune and voltages ever so slight can make it run wonky

Also check O2 sensor

And run a ground wire from coil packs to firewall

with cover off turn off the lights and run the engine you can sometimes see the culprit spark jumper

My splitfires played up after 2 years doing the miss fire and abs, slip, tcs warning to come on The dash

Confirm no boost leaks or vacuum leaks as well

Fuel regulator if its tee'd off for boost gauge , dont do that return to factory setup it can surge and fry a motor if it pops off

And of course fuel filter

And fuel brewed last week is different mix then this weeks cold weather batch if you didnt know that ??

[Madaz]

yes you are quote prabably correct Troy

http://www.skylinesaustralia.com/forums/topic/110431-diy-aac-valve-cleaning-idle-reset/page__hl__idle%20air%20control%20valve

[Carbon 34]

Could be a bad spray pattern on injector as well , leaking a tiny bit

[Carbon 34]

Does it have nismo thermostat low temp? That on nistune causes issues until its hot as hell too

the laptop kept saying low temp on mine while on

Dyno 35c day , no issues on cold day so far just smells rich as hell for the first 2 km

My car only had 74,000km and it was caked with crap , injector cleaner wont fix that idle air problem either the injection happens below that

[DC_GTST]

going fast and stopping fast are too different things

and i don't drive that fast like i used to either... remember all eyes are on Steve when I'm out and about

Dan - the R34 wouldn't have an igniter they are built into the coil packs since S2 RB25

Cheers Steve - Lesson learned.....

[Tbetts]

Its the ilde air control on the back of the manifold is carbon caked that controls idle air and cold start driveability

backside of throttle plate is most likely as well , check the TPS its a touchy bastard with nistune and voltages ever so slight can make it run wonky

Also check O2 sensor

And run a ground wire from coil packs to firewall

with cover off turn off the lights and run the engine you can sometimes see the culprit spark jumper

My splitfires played up after 2 years doing the miss fire and abs, slip, tcs warning to come on The dash

Confirm no boost leaks or vacuum leaks as well

Fuel regulator if its tee'd off for boost gauge , dont do that return to factory setup it can surge and fry a motor if it pops off

And of course fuel filter

And fuel brewed last week is different mix then this weeks cold weather batch if you didnt know that ??

My mate had similar issues with his WRX and it turned out to be the o2 sensor or talk to Morrie at Horse Power in a Box that guy is a legend other wise i agree with everything stated in the post above.

[Carbon 34]

Ashley at classic chassis and dyno in hackam , he has a Gtt so he knows them well

Nice guys who go above and beyond to do it right not time clock watchers who punch out at 4:30 like a few ive run across

But im pretty sure you will find the problem as above

Unless your wiring harness is knackered , nissan is bad for that in out vintage of cars in this climate

If the car is throwing codes even that can be a goose chase of intertwined ecu functions and not cut and dry fix.

No codes thrown , my money is on idle control and throttleplate ( unless it has greddy manafold)

The 34 O2 can be swapped with some wiring hack for another model , mine was shagged ,2 in 4 years , the r31 i just sand it back slap it in its lasted since car was new in 89 still the original one Still going strong

[camoo]

Its the ilde air control on the back of the manifold is carbon caked that controls idle air and cold start driveability

backside of throttle plate is most likely as well , check the TPS its a touchy bastard with nistune and voltages ever so slight can make it run wonky

Also check O2 sensor

And run a ground wire from coil packs to firewall

with cover off turn off the lights and run the engine you can sometimes see the culprit spark jumper

My splitfires played up after 2 years doing the miss fire and abs, slip, tcs warning to come on The dash

Confirm no boost leaks or vacuum leaks as well

Fuel regulator if its tee'd off for boost gauge , dont do that return to factory setup it can surge and fry a motor if it pops off

And of course fuel filter

And fuel brewed last week is different mix then this weeks cold weather batch if you didnt know that ??

Ashley at classic chassis and dyno in hackam , he has a Gtt so he knows them well

Nice guys who go above and beyond to do it right not time clock watchers who punch out at 4:30 like a few ive run across

But im pretty sure you will find the problem as above

Unless your wiring harness is knackered , nissan is bad for that in out vintage of cars in this climate

If the car is throwing codes even that can be a goose chase of intertwined ecu functions and not cut and dry fix.

No codes thrown , my money is on idle control and throttleplate ( unless it has greddy manafold)

The 34 O2 can be swapped with some wiring hack for another model , mine was shagged ,2 in 4 years , the r31 i just sand it back slap it in its lasted since car was new in 89 still the original one Still going strong

Hey mate, i need u on speed dial ha ha ha.

Ok so i already checked the IAC valve, cleaned and replaced a while ago chasing this, and didnt work.

Im more inclined to the TPS, but i thought that would be show any issues while tuning, and my tuner would clearly see it? i may be wrong...

Either way does anyone here know how to check the TPS on my car?

O2 sensor is good.

No sparks in the dark, and i ran an extra earth lead from my coils when i installed them.

Ive checked leakes with break cleaner, are there any better ways?

My FPR is TEE'd off for my Profec B...

New fuel filter last week with its service.

N yeh i know fuel changes, but nothing we can do bout that, much like the price HAHA!

I might take it to see Ashley, if he has a 34, id hope he will be able to help.

Thanks everyone for all your input, keep it comin!!

[V28VX37]

...

Thanks everyone for all your input, keep it comin!!

Something a bit left field, have you checked your Crank Angle Sensor? Mine was stuffed and was very difficult to diagnose, read more here.

Good luck!

Edited April 24, 2012 by V28VX37