R34 Misfiring And Hard Start When Hot.

[owen1r]

Hi guys,

My R34 GT-T is misfiring in the higher rpms when the oil temp gets around 105-110 ish degrees (on the stock gauge), the hotter it gets the earlier the missfire starts to happen. Mostly it happens just before redline, but sometimes it will misfire as early as 5500 normally hotter the air temp the worse it is. There is also a slight missfire on idle/low rpms.

If I try and start the car when it is hot, It takes ages to start and will pop and backfire occasionally. Sometimes it starts for a few seconds and revs at about 500rpm then dies out again unless I give it a tad of throttle.

The car drives flawlessly when cooler (around 90 deg oil temp), no issues whatsoever.

Details about the car

- Replaced Coilpacks and Loom with splitfires, yellow jacket loom.

- New Spark plugs 2000 kms ago, NGK Coppers BCPR6ES

- New Walbro GSS342 with direct wiring, Fuel filter

- Front Mount intercooler

- Stock ECU

- 3 Inch TBE

- Running 6/10 psi (high/low boost), the issue occurs if I'm running either boost pressure.

- Recently replaced O2 sensor

- Cleaned the AFM

I have hooked up the car to nissan consult and the sensors all seem to be working correctly, I have not encountered a check engine light or error code.

Anyone got any ideas?

Much appreciated.

Edited February 18, 2014 by owen1r

[Josh080691]

My initial thought would be to try a different cas. I had similar problems on my 33

[owen1r]

Will grab one to test it out.

Could it be AFM dry solder joints?

[owen1r]

Car is fixed, swapped over the CAS and it fired right up and no misfiring up top

Still slight misfire/pops on idle and low rpm but this must be unrelated.