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Misfire / engine sputter on cold eng start

blackanator

By blackanator,
in Engines & Forced Induction

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blackanator Enthusiast

blackanator

Posted
Posted

Hey guys, i have a 89 gtr and i seem to be having a misfiring/sputter problem when cold started.

Say if i were to start the car in the morning, the car drives normally, til you hit about 2nd gear, then after about 2000rpm the exhaust sputters / back fires quite a heap til you get about 2.7K - 3K - giving it a bit seems to get it out of the rut, but once u get to the next gear it seems to do it again as soon as you get over 2000rpm. It seems to run rich and u get a little bit of smoke goin. Even when i get over this, u still get the once and a again u get the small pop / slight backfire when you change gears (which is normal yeah?).

This usually lasts about 3-5 mins at the start of the drive.

I have been reading up on the forums, and i have changed the spark plugs, they were faily normal, nothing too black or stuffed etc, but we changed them anyway for some NGK's we spaced at .8 from supa dupa cheap. After changing them it seems to still do this.

Sorry if ive given very vague information, but any help/suggestions would be appreciated muchly. Before goin down to my mechanic, i jsut thought id like to try work out what the problem is/ so maybe i could fixit (highly unlikely :)) or can better explain to my mech the problem.

Cheers.

EDIT: sorry forgot to mention, when it is sputtering/backfiring etc u can feel slight power surge, feel it kinda struggle etc, but yeh as i said you get out of it by giving it a bit more.

  • 2 months later...
super26 Apprentice

super26

Posted
Posted
I have this exact Problem, ive replaced sparkplugs, O2 sensor, taped up coil packs allthe usual stuff to no avail, infact its got even worse.

Have you solved it?

Have you tried the temperature sensor for the computer, because when the car is cold it is goin to run ritch and as it heats up it is goin to lean out a little bit, so in your case may be it is staying rich jus a tought.
Rolls Grand Master

Rolls

Posted
Posted
Your temp sensor could be on the way out.  Mine has a habit of doing exactly the same thing so I'll be interested to see if replacing it fixes the problem.

LW.

Where abouts is the temp sensor, also what would be the correct way to test an AFM, multimeter resistance test?

cheers, also its a redtop eccs rb20det R31 motor

Also took it for a spin tonight and it misfired extremely badly around 4-5k a few times, then got better.

  • 2 years later...
  • 3 months later...
bumble_bee Rising Star

bumble_bee

Posted
Posted

wat engine is is required for a r33 skyline??

like is there a universal type avail. from a local repco etc..???

becoz my mate temp. sensor went..he went to repco and got a universal type that fitted..

but wat about voltage requirements/temp requirements etc????

  • 8 months later...
Dohmar Grand Master

Dohmar

Posted
Posted
woops....

i was takin about water temperature sensor....

bumping this thread as I've been having the same issues. Have replaced all my spark plugs and have identified a leaky injector and two coilpacks that are on the way out - however since this happens in the first 10 minutes of a drive then I believe that those two components aren't the culprit...

where is this water temperature sensor located? I've plugged the consult cable in to check the error codes and everything reports to be OK... or it could be a failing AFM.... not sure... any help appreciated...

-D

Dohmar Grand Master

Dohmar

Posted
Posted (edited)
when it splutters , does tapping the accelerate quickly restore itm or it goes back to splutter?

sometimes tapping it does. it seems to splutter during acceleration with power loss but if i slam the accelerator down it doesnt disappear... its like it has no torque and doesnt accelerate when under gear but when the clutch is down it free revs as normal

and if i have a constant speed of 60kph you can feel the lack of power and the stuttering.... and when it 'decides' to change after 5-6 minutes of driving, the same accelerator position means i start to gain speed instead of just maintaining speed, and the revving of the engine starts to take a more normal tone and response is back to normal. i had these symptoms a few months ago but the duration and severity of the powerloss is increasing over time...

-D

Edit : should also add, when i put the accelerator down a bit more to try and get the engine to accelerate during this time, the exhaust sounds like its spitting exhaust gasses in pulses.... i can feel/hear the put put put sound rather than a purr if i back off the accelerator - its baffling to me - and its idling >perfectly< at the moment (ever since i replaced the sparkplugs, which didnt fix this current problem)

Edited by Dohmar
smidy Community Regular

smidy

Posted
Posted

got the same sort of thing but i was travelling at a decent pace for a while and the engine was probly warmer than usual. i am thinking it may be the o2 sensor in the exhaust (dumppipe). how regularly do you need to change the o2 sensor??? totally standard r33 rb25 and if i get a power fc or vipec computer upgrade will this solve alot of the coughing splutter, rich and retard engine problems through initial tuning????? :)

thanks

  • 3 months later...
Newy Collaborator

Newy

Posted
Posted

great thread, i also have the same issue. After the car running for about 10-15minutes its perfect. It's not a big issue, as i like to warm the car up well and truely anyway, but its rather more intreaging me lol!

side note: the car seems to take a very long time to get warmth into it, as apposed to my old r33

rob82 Mentor

rob82

Posted
Posted

I've got the same issue - its a catalyist light up function I think.

If you log the ignition timing you'll see that it runs alot less timing than what it runs when its up to temperature. The only other thing it could be is a nuetral switch not working.

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