Stalling At Idle And Spluttering During Acceleration?

[R32.GTR]

hey guys, i have a r32 gtr which has been running a bit weird latetly.

at first it was occasionally about once a week, but now its getting more common, like at least everytime i drive it.

cold mornings its fine, once it starts warming up is when the problem occurs.

i first noticed it when i parked my car, let the turbo timer do its thing then just as i was walking away it started spluttering at idle, did that for 5 seconds then regained normal idle. it also did this while waiting at a set of traffice lights (even while i was rolling upto them) blip the throttle a few times and it sometimes goes back to normal idle.

why is it doin this?? its VERY annoying, ive even swapped the idle position sensor and still had the same problem.

also say im just driving down the road, it will even splutter (like its out of fuel?) nd have no response on throttle. then as im trying to accelerate in gear (while still doin speed limit, slowly gettin slower) it sounds like it misfires. sometimes this goes on for 5 mins and i cant even drive it, and other times its over in 10 seconds? then back to prefectly normal.

even if you hold your foot in the same spot on the accelerator pedal, it will cut out, accelerate, cut out etc..

i seriously have no idea whats wrong with it.. fuel pump? something to do with idle control? but that wont help the problem while at speed? it could be 2 different problems.

if anyone could help that would be GREATLY appreciated

Cheers.

[BoyWhoCriedWolf]

Check the following:

Plugs

Coils/igniter <I reckon its this.

AFM

Be sure there are no IC leaks either.

[Mohsen]

mines doing the same thing, all the time

maybe your coil packs?

[Rob_32_VSPEC]

my moneys on AFM

[fib]

Also check the cam angle sensor, you can just unbolt it and have a look. Mine had broken teeth causing this, replaced with $100 second hand CAS and worked fine.

[GTRPowa]

Also check the cam angle sensor, you can just unbolt it and have a look. Mine had broken teeth causing this, replaced with $100 second hand CAS and worked fine.

^ When I changed the turbos it started fine, misfired after 20 mins, started feeling like you were turning the ignition on/off etc. I checked afm's, cleaned injectors, filter, ignition module, etc. Replaced the CAS with a mates, still no go, changed back to mine, worked fine. Turned out the plug for the CAS just needed a wiggle/twist. Dunno if your prob is the same but,

Coils: I'd unplug one coil to see if it sounds different/makes it worse. Check each coil, takes but a few mins.

AFM: I'd simply get AFM cleaner and clean it anyways, if it's the stock one. Few bucks, worth it.

CAS: Wiggle the plug/Unplug and reseat. Borrow one from a friend before spending money on replacement.

Fuel Filter: Cheap, but nasty to replace if you have big hands.

Plugs: How old?

[R32.GTR]

cheers guys, its hard to diagnose cos its not always happening, just sometimes desides to do it.

wiggled/unplugged the CAS - same

its not the coils either, checked them

plugs are probly due for a change, but that would make it run shit all the time? or not?

but when i un-plugged the AFM it started to run shitty, exactly like the problem i explained above.. then after a few seconds it regains idle but wont rev over a few thousand revs, (not crisp anyway)

is there any sort of tests for AFM?? to see if they working correctly? or faulty?

[BoyWhoCriedWolf]

OK, borrow an igniter from someone. I reckon this is it from the symptoms you have explained.

[R32.GTR]

thanks, will try to find an igniter and see how it goes.

but how do you know if the AFMs are dodgy? any way of telling? or just have to swap nd see?

[BoyWhoCriedWolf]

swap for a proven pair and test or get a PowerFC and check the PIM voltage of each afm

[typevu]

My GTR did the same thing and it was the AFM. I cleaned it out with some contact cleaner - can be purchased at dick smiths electronics.

[DAS KAMU]

My GTR did the same thing and it was the AFM. I cleaned it out with some contact cleaner - can be purchased at dick smiths electronics.

i had the same thing

was afms

[R32.GTR]

just swapped the AFMs with another working pair from another GTR, seems to be working perfectly fine atm.

hopefully this is the problem! nothing worse than not knowing what the hell is wrong, hate guess work haha

need to find a set of AFMs now, or find out which one was faulty if not both.

thanks alot guys!

Cheers.

[BoyWhoCriedWolf]

just swapped the AFMs with another working pair from another GTR, seems to be working perfectly fine atm.

hopefully this is the problem! nothing worse than not knowing what the hell is wrong, hate guess work haha

need to find a set of AFMs now, or find out which one was faulty if not both.

thanks alot guys!

Cheers.

Id replace both. If you do try to buy a set of nismo ones, they are more expensive but have the same characteristics of a Z32 meter which is good if you make some more serious mods to the motor.

[R32.GTR]

Yeh I was looking at some nismo ones, still not sure yet.. Either quick and cheaper fix with STD ones or upgrade to z32 or nismo and get it re tuned. I do wana upgrade the engine later down the track tho, but my pockets arnt deep enough at the moment hah

May go for the cheap fix first then upgrade a bit later on

Cheers mate

[BoyWhoCriedWolf]

When you do start looking at new afms get the Nismo ones, that way you will be able to bolt and ARC air box in, the Z32 AFMs dont fit.

[R32.GTR]

yeh nismo were my preffered choice, very $$ tho haha.. but GTRs aint cheap lol

whats the ARC airbox?

[BoyWhoCriedWolf]

Good shit.

[R32.GTR]

fair enough.. looks serious! haha

i just got HKS pods, lookin to change to the Apexi setup.. will get onto nismo ones soon!

but in the meantime will std AFMs from a Aus delivered GTR work on an imported GTR? i was just wondering if they are diff?? probs a stupid question but am just curious?

cheers

[BoyWhoCriedWolf]

Should work fine, there is nothing the Aus suplementry that mentions anything about different afms.