Car Stuttering Badly!

[R-SPEC]

ok its a r34 gtt with basic bolt on mods on 12psi

first thing i noticed was on mainly cold starts on idle it stutters and pops at the exhaust

then i noticed on gentle driving it accelerates smoothly, but once i put my foot down it stutters badly and goes no where.

this happens when i hit full boost mainly

i was thinking shit spark plugs?

would appreciate any help asap

[paulr33]

whats changed? has it always done this? when was it last "ok" ?

[R-SPEC]

the pops in the exhaust have been there for aslong as i remember.

the stutter on idle on cold starts i noticed it about a week or 2 after the timing belt and water pump were replaced with new ones.

this part "on gentle driving it accelerates smoothly, but once i put my foot down it stutters badly and goes no where.

this happens when i hit full boost mainly" i noticed it months ago but has been getting worse ever since...

i have changed the intake pipe a couple of times during the past few months (from rubber to steel to rubber and now rubber with steel piece in it.

i also changed the afm (mine broke) and put stock airbox back on. i did this a few days before the timing belt was replaced

[sickr33]

put new spark plugs in 0.8mm gap

if it still pops you need new coilpacks

[RBceffy25]

put new spark plugs in 0.8mm gap

if it still pops you need new coilpacks

I second that!

your popping exhaust might also be a leaking gasket.

[TiTAN]

i had that problem and it was a cell on the ecu that hadnt got enough fuel so it would go lean and lose almost all power and make some popping noises in the exhaust.

[R-SPEC]

will change the plugs tomorow. thanks

i had that problem and it was a cell on the ecu that hadnt got enough fuel so it would go lean and lose almost all power and make some popping noises in the exhaust.

how did you fix it?

[The Dan]

Something else you should consider is the factory 12.5psi boost cut.

Will cause major issues while at full boost.

Although, it does sound like a vacuum leak causing the dodgey idle etc.

Check for vacuum hoses that you might have not reconnected and check to make sure the timing has been set correctly. You may have just one problem causing everything or you may have a few problems all working together.

[TiTAN]

will change the plugs tomorow. thanks

how did you fix it?

you add more fuel to the cell that doesnt have enough. though that wont be the issue if you are still using the stock ECU.

[skyguy61]

Hey There,

I had the same thing happen to mine after having the timing belt and water pump done, turned out it was the ignition timing was out by a quite a bit. I was thinking coil packs,sparks plugs,fuel pump etc $$$$ before finding the timing was out, I'd get your timing checked before running out and spending money unnecessarily. Hope that might help. cheers

[paulr33]

agree with skyguy

if its all just changed after timing belt change which is a key change, logic says something has gone wrong here

check the basics, check it with a timing light at idle

[skyguy61]

Thanks Paul,

I was quite pissed off considering that a Japanese mechanic did the job!! and he didn't reset the timing after reassembly. Needless to say they didn't get anymore work from Moi.

[chalky]

what if ive fixed all that and even running 8-10 psi on a r32 with r33 stock turbo it still stutters mainly under full boost or whenever i give it up.

[paulr33]

well it can only be a few things

air, fuel, spark

so check there, look for something simple / obvious

[sickr33]

something to keep in mind is fuel filter

i change mine every second or third oil change approx every 15k

you would be surprised how blocked they get

and can cause you to lean out under full load