Engine Stuggles Above 2000 Rpm

[Dre678]

Hi All,

I've got a totally stock R33 GTS-T and recently when pulling away from the lights the car struggled to accelerate past 2k RPM.

I'll have my foot flat on the throttle (and shows and sounds like the turbo is at full boost) but the revs go very very slowly above 2RPM and there's obviously no pull - no matter what gear i'm in.

I've changed my coilpacks about a month ago and the current problem doesn't seem like a misfire as such, it feels as though my foot is only slightly down on the gas (even though it's flat!!)

Is this the sign of a faulty AFM?? I don't think there's any smoke, but there's a bit of a odd smell when I pull up - the smell could, however, just be me haha

Any advice?

[SargeRX8]

It can be dodgy afm. 2krpm is the limp mode for the car. If it has a stock ECU stick a consult in it and see if has any issues. Do you get any engine check light? Could be many things causing this, boost leak, dodgy accelerator cable not opening the throttle, faulty afm, faulty injectors, misfire etc.

[Dre678]

Thanks for the reply bud.

It does indeed have a stock ECU. The problem occurred once last week must seems permanent now :s

Every once in a while it shoots past 2000 RPM but 90% of the time she struggles. Very frustrating!

[markdem]

i had a similar problem. my stagea (r33 s2) occasionally wouldnt accelerate beyond 1500rpm. it was something to do with the fuel conservation mode the car goes into on idle - it was getting stuck in that mode! which was of course limiting fuel delivery and therefore power.

i fixed it by bypassing the dropping resistor and making the fuel pump go full pressure all the time

[rondofj]

Do u have a rag or anything blocking the cooler/intake pipes??? Or any blockage in the exhaust?

[Dre678]

I did have a service last week (just changed engine oil, tranny oil and coolant) but she was ok for a day or two after that...

Also I had switched to Yellow Jacket coil packs about a month ago...

I haven't looked for any blockages as yet. Will do so tonight

[HtwCHACtkh]

Hello Dre678,

I can tell you it's not a faulty AFM as when they go bad the R33 ECU (At least in my car) won't let the car go past 4500 RPM and it's a hard jolt like hitting a rev limiter.

I would be more inclined to think it's related to boost at the moment as 2000 rpm is around when the stock turbo kicks in. Can you drive high RPM low boost? i.e. Very little throttle, Low gear. But really I know nothing more than it's not a faulty AFM.

You can try an ECU reset, it's completely harmless. (Check the forced induction quick reference guide)

Cheers

[DVS JEZ]

Check the throttle is opening fully when u press the pedal down.

Check TPS settings and base timing etc.

Is there any black smoke when it struggles to rev?

Check airfilter and catalytic converter

[Dre678]

Thanks Aqeul and Jez,

I did try to keep the throttle slightly open in a low gear - it did creep past 3000 RPM but it didn't last for long as soon as the boost kicked in.

I haven't noticed any plooms of smoke when pulling away but obviously that's something I can miss.

I'll check out the cable tonight and might try the ECU reset too. I've got it booked in at a skyline shop tomorrow but obviously I'd rather solve it myself...

I don't know much about the throttle position sensor, but i'll do a search here.

Thanks again for the advice.

[Bsa]

Did you change your plugs bad plugs?

Edited November 17, 2011 by Bsa

[Dre678]

Nah mate, I only did the coilpacks as the plugs were changed not that long ago.

[HtwCHACtkh]

I did try to keep the throttle slightly open in a low gear - it did creep past 3000 RPM but it didn't last for long as soon as the boost kicked in.

Wind boost down to a dead stock level by running boost pressure straight to the actuator just to test.

Google will have lots of info on the throttle position sensor, it's worth checking your throttle body. Though if it can rev to redline in neutral very quickly with WOT though I would imagine it's not throttle body problem and more of a "tune" problem.

If you reset your ECU with a paper clip like in the how to on the sticky in the forced induction section it will give you self diagnostics by flashing the check engine light slowly "x" number of times and quickly "y" number of times to give you an error code "x,y" that can help you diagnose if it's a faulty sensor.

EDIT:

Resetting ECU: http://www.skylinesaustralia.com/forums/topic/2879-resestting-ecu/page__view__findpost__p__3262978

Error Codes: http://www.skylinesaustralia.com/forums/topic/2879-resestting-ecu/page__view__findpost__p__1699249

[chocco]

Timing is out by the sounds of it

[Dre678]

Wind boost down to a dead stock level by running boost pressure straight to the actuator just to test.

Google will have lots of info on the throttle position sensor, it's worth checking your throttle body. Though if it can rev to redline in neutral very quickly with WOT though I would imagine it's not throttle body problem and more of a "tune" problem.

If you reset your ECU with a paper clip like in the how to on the sticky in the forced induction section it will give you self diagnostics by flashing the check engine light slowly "x" number of times and quickly "y" number of times to give you an error code "x,y" that can help you diagnose if it's a faulty sensor.

EDIT:

Resetting ECU: http://www.skylinesa...ost__p__3262978

Error Codes: http://www.skylinesa...ost__p__1699249

Yep, in neutral there was no problem - the problem only occurred when in gear.

So I followed your advice and reset the ECU. It return a 55 code (which I read means all is ok) I went for a drive (a hard one) and it seemed to have done the trick.

I'll go for a drive tomorrow and i'll rack up plenty of km's over the weekend so here's hoping the problem has been solved! Thanks for all the advice!

[Dylaan]

I had this problem today when I drove my car, I called my mechanic and he thinks it may have picked up bad fuel or had a blocked fuel filter. The problem seemed to go away after I put new fuel in it and cleaned the afm. I hope it's not planning on coming back!