R33 Gtr Missing At 3500rpm

[manage13]

Hi All,

I have a bit of an issue I can't put my finger on and I am hoping the SAU community can help.

I recently imported a 33 GTR and when I drive the car and keep it at a steady 3500 rpm there's a miss. Below and over 2500 rmp the car runs ok. Having said that the fuel consumption is very bad and there's plenty of back fire in normal driving.

I have done my home work and searched on this site and Google and the below have been helpful but not solved my issue.

• (32 Gtr) Odd Missfiring At Low Revs (idle To 3k)
• R32 Gtr Misfiring Spluttering And Chewing Fuel
• GTR RB26 Misfire Under Boost and Coil Pack Fix

What I have done:

• Changed spark plugs to NGK BCPR7ES which I chose after reading a thread on SAU
• Changed the fuel filter
• Changed the CAS
• Changed the pod filters to airbox
• Changed AFM
• Changed BOV's and checked piping was on tight
• Changed the coil packs and sealed them with dielectric goo as the YouTube video suggested

The car sounds a little rough on idle but I am not sure if this is because the cam timing as the in was set to 0 and ex 2 degrees retarded. I noticed this when I did a full service on the car and I changed my timing belt. HKS cam gears came as a surprise. (the car was missing before the service)

The only thing I haven't changed is my injectors and fuel reg as one of the topics said that possibly could be the issue.

Before I start removing the fuel rail, injectors and reg is there anything else that could be causing this issue?

All your input will be greatly appreciated as I am stumped!

Thanking everyone in advanced.

[GTSBoy]

Vacuum leaks. Throttle body shaft sealing. Just 2 more suspects that come to mind.

[Hadouken]

i presume everything was changed out with know working/ new items....

[GTRPSI]

Most likely a vacuum/boost leak.

Last time i had a miss it was the igniter module, in my case it was above 3500 but sounded like the wide spark gap or faulty coil pack issue.

In your case with backfire it sounds more like a Vacuum or boost leak, you need to check your hoses and pipes first.

[manage13]

Thanks guys!

I think you might be right about the vacuum leak as I believe the brakes are not as good as they should be. I have found a workshop that has a vac leak tester (think it's called a smoke test) and have a booking on Monday.

Having said that though I used carby cleaner and sprayed around hoses but I didn't notice anything.

Will keep you posted on the results/ solution.

Edited July 14, 2015 by manage13

[manage13]

Well it's not a vacuum leak; just had a smoke test done by sabbadin.

TPS? You know if a 3 2GTR TPS is interchangeable with R33 GTR TPS?

[STATUS]

Dead or failing o2 sensors do all those things...

[manage13]

Dead or failing o2 sensors do all those things...

Hi Trent,

Thanks for your response. Does the engine light come on when an 0₂ sensor fails? Currently I don't have the warning light. Also, if I plug a diagnostics tool will I be able to tell if the O₂ sensor is failing?

Thanks.

[Hadouken]

Just unplug them and see if the miss is gone. This is called open loop.

[R31Nismoid]

Dead or failing o2 sensors do all those things...

+1.

That's my bet as well!

[XRATED]

.. r33 GTR missing at 3500rpm!

2 questions:

- Where did it go? I assume it came back/

- Do you have a picture of the flux capacitor install?

Cheers

Justin

[manage13]

.. r33 GTR missing at 3500rpm!

2 questions:

- Where did it go? I assume it came back/

- Do you have a picture of the flux capacitor install?

Cheers

Justin

LMFAO! I'll pay that one.

Just unplug them and see if the miss is gone. This is called open loop.

Oh I already did this a few weeks ago and the miss was still there.

[manage13]

Ran the car again on open loop and still the miss is there... slightly!

Could this be a CAT blockage?

[R31Nismoid]

Would think it to be fairly unlikely.

Worth checking of course

[Count Grantleyish]

Thanks guys!

I think you might be right about the vacuum leak as I believe the brakes are not as good as they should be.

What do you mean by brakes not as good as they should be?

As in making hissing (or bubbling) noise when it comes to complete stop as you'd felt on the pedal?

[manage13]

Hey guys,

I put a PowerFC in and the miss is gone. I think it may have been an ECU issue.

@Count Grantleyish, the car doesn't pull up as well as I think it should. If that makes sense?

[KiwiRS4T]

Do the brakes get better with a few hard stops or do they fade? It is worth changing your brake fluid (any new fluid but something like Motul best). Otherwise a change of pads might be indicated. They could be track pads which don't pull up well when cold or they could be just rubbish pads (have a read of the brakes section for some suggestions) - I bought Pagid but they are quite expensive and there are other types that people like.