R34 Gtt- Load Hesitation

[agags333]

Hey Guys

ive noticed misfiring and or hesitation from my car when planting the accelerator.

this occurs on high RPM range - 4.5 onwards when in low gear, and also occurs on LOW RPM when im on freeway win 5th gear and decide to plant the pedal.

Any ideas?

The car basically "struggles" as if not all pistons are firing.

[Blackkers]

This could be one or two of many things. What is your set up?

How much boost? What turbo and what Ecu? Spark plug gaps? Coilpacks?

If you haven't done it in a while just fit a new set of NGK copper plugs

[agags333]

everything , except for an HKS POD filter, is stock.

i have recently services the car with BCPR6ES 11s thinking the 8s i had in there could have been the problem.

to no avail.

I can try changing the coilpacks i suppose.

but from what ive read, looks like timing, maybe if i adjust CAS?

[XGTRX]

Does it blow black smoke when it comes on

[agags333]

No smoke, no backfiring, just sounds and feels like its all in front.

[Marcus89]

Most likely worn out coilpacks then

[Dose Pipe Sutututu]

Borrow some coil packs

[agags333]

k will try this thanks

[agags333]

ive noticed it happens on full throttle. not on half or steady acceleration

[GH05T]

i have coilpacks, link bellow

[Daffy]

have you gapped the plugs right? sounds like they are not, close the gap some. Higher compression needs closer plug gaps to fire

[Kinks]

If it's a bit rough and stuttery, coil packs for sure. Also, if you coil packs are worn then gapping the plugs down to 0.8 will help. There should be no driveability issues with 0.8 gap, everyone does it. Ultimately you're just delaying buying new coil packs though.

HKS pod could be releasing oil onto your airflow meter. get some electronic cleaning solvent (NOT PCB cleaner, just cleaning solvent that says it dries without residue) and hit your airflow meter with it. the hot wire inside the airflow.

if it's smooth (like the car just feel gutless) it could be rich and retard. my car seems to drop timing in the midrange, stock ECU stock everything. go figure. just has a big hole. I'm replacing the ECU at some point so will see if it takes more timing on the dyno.

[nicksamaniac]

The bcpr6es 11s you got, the 11 is the gap set out of the box- 1.1mm, you can try closing it to 0.8mm as kinks said.

Everybody does it and seems to work for everyone.

Science tells us that gas is harder to ionize at pressure, hence closing the gap helps.

[V28VX37]

I had a high RPM breakdown occurring that was caused by faulty CAS: http://www.skylinesaustralia.com/forums/topic/326043-resolved-misfire-in-r34-gtt-rb25det-neo/

RB's are awesome (not) in that they can misfire for any number of random reasons, bastard to diagnose.