r32 gtr idle misfire when hot

[ck_chino]

Hey Gents

As the car is warmed up not only coolant temp but also oil temp, say around 80-90  degrees the car starts to have a misfire.  At first its just a hiccup at idle but then progressively gets worst as I keep driving and the engine warms up more.  From idle to 1500 rpm the response is terribly.  It's extremely hard to take off from a light, and the whole drive line shudders as I attempt to get the car moving but as soon as 1600 rpm rolls around it goes back to absolute normal with no problems all the way WOT and mind you this only happens when the oil temps are at operating temps avg 85 degrees.  Does this seem like an igniter issue?  or coil pack issue.  Whilst this happened, I had the car on the driveway with the engine running and I sprayed freeze spray directly onto  the igniter with no change.  From 1600rpm and up theres no issue, regardless of coolant and oil temp.  My intent is to go r34 gtr smart coils and get the wiring specialites adapter harness and be done with it,  just hope this helps.  Thanks guys

[Dobz]

What ecu? Sounds like it could be tune related if it clears up at higher revs.

[ck_chino]

haltech plug in.  has been tuned for 2 years, this is the first time it has given me trouble.  

single turbo

maf deleted running onboard map sensor

gm iat

 

update= the car now is unable to rev past 2000rpm, just struggles to rise to 2000rpm, sounds like anti-lag(double hecked its not activated).  

can a failing ignition system change symptoms so erratically?

[ck_chino]

 

update: Started again this morning no faults revved to 5-6000 no issue, ran for about 10 mins, I shut it down.  Went inside to have a bite and then come back out to start it and the problem re-appears.  Seems something gets heat soaked and it struggles to get to 1750 rpm from idle, then as it approaqches 1750rpm, it will clean right up and rev no problem.  During the stumbling, the afr gets really lean basically offscale.  If it was a vacuum leak would the engine rpm be higher?  I see no decrease of vacuum on my aem boost gauge, it sits at a steady 20in/hg. 

[msammut]

Could be the PTU. Can you try another one?

Michael

[Trex]

Take a log and post it here

[ck_chino]

hey guys

 

update, so in went new coils and no joy, same symptom when hot.  I opened up the cas and found a whole bunch of rust dust inside, bearing seems shot.  blast of air, back on car and it seems good now.  no more bucking or loss of power.  no my other question is how do i rebuild a hitachi cas(r32/r33 style.  not the black one on the r34)?  i pulled off the cover which mounts to the cas bracket but the guts of it dont seem to want to conme off even after removing the screws.  any ideas guys?