Jump to content
SAU Community

R33 Gtst Cutting Out At 4000rpm

tomgtr

By tomgtr,
in Engines & Forced Induction

 Share

Recommended Posts

**RB2530** Proficient

**RB2530**

Posted
Posted
hi all, new to the forum just bought an r33 last week. It has a problem where it doesnt want to run over 4000rpm. As soon as it hits it the car stutters and jumps around with the revs bouncing and just wont rev any more. Any ideas?

cheers

Tom

Do a search for 'air flow cut'....

Dose Pipe Sutututu Grand Master

Dose Pipe Sutututu

Posted
Posted

If it's a stock ECU, sounds like it's on LIMP mode, this occurs when the AFM is faulty or disconnected.

Disconnected cooler piping will result in a fked up idle, leaking cooler piping usually doesn't cut out at 4000rpm, car just runs like a POS

bubba Grand Master

bubba

Posted
Posted

He didn't say it cuts out, he said it coughs and splutters and I HAVE had that happen from a leaking cooler pipe, it was basically a clamp not tightened up, it would be fine until it built enough boost to pop open the leak and then died in the ass (hence asking about it belching heaps of black smoke).

And doesn't limp mode limit to about 2000rpm? 4-5000rpm is usually spark breaking down.. particularly with the coughing and spluttering.

AFM over voltage cut is a harsh CUT similar to the overspeed cut, not coughing and spluttering.

**RB2530** Proficient

**RB2530**

Posted
Posted
If it's a stock ECU, sounds like it's on LIMP mode, this occurs when the AFM is faulty or disconnected.

Disconnected cooler piping will result in a fked up idle, leaking cooler piping usually doesn't cut out at 4000rpm, car just runs like a POS

If it is badly leaking (disconnected) intake pipework I doubt very much you could get the engine to rev to 4000rpm.

If it is a moderate leak (split hose connector hose etc) TC will spool more as it is not loaded as much by the back pressure of the intake. This will still cause excessive air flow through AFM and trigger airflow cut.

**RB2530** Proficient

**RB2530**

Posted
Posted
He didn't say it cuts out, he said it coughs and splutters and I HAVE had that happen from a leaking cooler pipe, it was basically a clamp not tightened up, it would be fine until it built enough boost to pop open the leak and then died in the ass (hence asking about it belching heaps of black smoke).

And doesn't limp mode limit to about 2000rpm? 4-5000rpm is usually spark breaking down.. particularly with the coughing and spluttering.

AFM over voltage cut is a harsh CUT similar to the overspeed cut, not coughing and spluttering.

AFM over voltage is a harsh cut but the reaction time for it to occur and for it to reset is very quick. From what I have seen Nissan don't have any damping or delay on its reistatement of spark / fuel.

In cases where airflow hits the cut threshold very hard (rising rate of air flow is high) , it really jolts the car around. Where if the airflow is close to reaching its peak anyway and is just on the threshold of cutting(threshold rises with rpm) you can get a coughing and spluttering.

The reason there is a difference is that the time taken for airflow to drop below the threshold cut level for both scenarios will be different due to airflow overshoot effects.. ie the higher the rising rate of airflow, the longer it will take for airflow to drop below threshold.

tomgtr Apprentice

tomgtr

Posted
  • Author
Posted (edited)

Yeah the car really jolts around its quite harsh, I have had it rev to over 6000 rpm a few times in one drive where it ran fine.

The car doesnt blow much smoke at all, and a few people have told me it could be a faulty pipe or something,

Thanks for the feedback it is very helpful

Edited by tomgtr
Sean W Experienced

Sean W

Posted
Posted

if you have any friends that own r33s (or you could ask around for kind members on here in the want to borrow section) you could switch their air flow meter for yours and their coilpacks for yours. if either solves your problem you know what to replace.

smokem31 Contributor

smokem31

Posted
Posted

not trying to hijack..... but have a similar problem....

if you put your boost lower, does it still do it?

cos mine is not as bad when running lower boost.... if i run 15psi, as soon as it spools up to 15, car jerks around and cant even drive it, just cuts in and out of power quite harshly.... but on low boost, 9psi, car just flat spots but still revs. see if that happens to you, cos i think its coils packs for me.... i changed plugs and regapped to .8 but still no good.....

dont think its injectors cos AF gauge reads rich while its coughing, jerking and spluttering....

hope it helps, and you can help me!

tomgtr Apprentice

tomgtr

Posted
  • Author
Posted

mines completely stock at the moment, but it runs perfect until it hit 4000rpm. Ill try the coil packs tommorow and check em out. Can anybody show me what the air flow meter is? I have no idea, this is my first import and only just learning.

thanks

tridentt150v Grand Master

tridentt150v

Posted
Posted
who ever is running 15psi needs shooting .

and do a search FFS

its f**ked coils

a f**ked afm will make the car not run over 2500 and sound like a rotor

Hahaha your so touchy feely lachlan, stop messing about and say it like it is................ :P

R33 Eddy Proficient

R33 Eddy

Posted
Posted
mines completely stock at the moment, but it runs perfect until it hit 4000rpm. Ill try the coil packs tommorow and check em out. Can anybody show me what the air flow meter is? I have no idea, this is my first import and only just learning.

thanks

make sure its not over boosting as it could be hitting the AFM threshold with stock ECU.. i used to run about 10psi and on really cold nights it would happen...

if that's all sweet then its your coils, check for cracks and tape them up if that fixes it then buy new coils :P

smokem31 Contributor

smokem31

Posted
Posted
who ever is running 15psi needs shooting .

and do a search FFS

its f**ked coils

a f**ked afm will make the car not run over 2500 and sound like a rotor

mind telling me why I should be shot for running 15psi, when you have no knowledge about my engine?

Trozzle Grand Master

Trozzle

Posted
Posted

Mind telling us why you shouldn't be shot, when you gave us no knowledge about your engine?

It's like asking why your turbo exploded at 30psi, without telling it it's a T51....you let us assume it's stock, so we're also going to assume you're an idiot.

smokem31 Contributor

smokem31

Posted
Posted

i gave no knowledge about my engine because it is somewhat irrelevant to the question at hand.

if someone was asking why their turbo exploded at 30psi you would obviously need to know what turbo they have.

my question was simple, is it worse with more boost?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • hoodedreeper
      Chris' Toyota Mark ii JZX110

      By hoodedreeper · Posted

      Next on the to-do list was an oil and filter change. Nothing exciting to add here except the oil filter is in a really stupid place (facing the engine mount/subframe/steering rack). GReddy do a relocation kit which puts it towards the gearbox, I would have preferred towards the front but there's obviously a lot more stuff there. Something I'll have to look at for the next service perhaps. First time using Valvoline oil, although I can't see it being any different to most other brands Nice... The oil filter location... At least the subframe wont rust any time soon I picked up a genuine fuel filter, this is part of the fuel pump assembly inside the fuel tank. Access can be found underneath the rear seat, you'll see this triangular cover Remove the 3x plastic 10mm nuts and lift the cover up, pushing the rubber grommet through The yellow fuel line clips push out in opposite directions, remove these completely. The two moulded fuel lines can now pull upwards to disconnect, along with the wire electrical plug. There's 8x 8mm bolts that secure the black retaining ring. The fuel pump assembly is now ready to lift out. Be mindful of the fuel hose on the side, the hose clamp on mine was catching the hose preventing it from lifting up The fuel pump/filter has an upper and lower section held on by 4 pressure clips. These did take a little bit of force, it sounded like the plastic tabs were going to break but they didn't (don't worry!) The lower section helps mount the fuel pump, there's a circular rubber gasket/grommet/seal thing on the bottom where the sock is. Undo the hose clip on the short fuel hose on the side to disconnect it from the 3 way distribution pipe to be able to lift the upper half away. Don't forget to unplug the fuel pump too! There's a few rubber O rings that will need transferring to the new filter housing, I show these in the video at the bottom of this write up. Reassembly is the reverse Here's a photo of the new filter installed, you'll be able to see where the tabs are more clearing against the yellow OEM plastic Once the assembly is re-installed, I turned the engine over a few times to help build up fuel pressure. I did panic when the car stopped turning over but I could hear the fuel pump making a noise. It eventually started and has been fine since. Found my 'lucky' coin underneath the rear seat too The Youtube video can be seen here: https://www.youtube.com/watch?v=uLJ65pmQt44&t=6s
    • hoodedreeper
      Chris' Toyota Mark ii JZX110

      By hoodedreeper · Posted

      It was picked up on the MOT/Inspection that the offside front wheel bearing had excessive play along with the ball joint. It made sense to do both sides so I sourced a pair of spare IS200 hubs to do the swap. Unfortunately I don't have any photos of the strip down but here's a quick run down. On the back of the hub is a large circular dust cover, using a flat head screw driver and a mallet I prised it off. Underneath will reveal a 32mm hub nut (impact gun recommended). With the hub nut removed the ABS ring can be removed (I ended up using a magnetic pick up tool to help). Next up is to remove the stub axle, this was a little trickier due to limited tools. I tried a 3 leg puller but the gap between the hub and stub axle wasn't enough for the legs to get in and under. Next option was a lump hammer and someone pulling the stub axle at the same time. After a few heavy hits it released. The lower bearing race had seized itself onto the stub axle, which was fine because I was replacing them anyway. With the upper bearing race removed and the grease cleaned off they looked like this The left one looked pristine inside but gave us the most trouble. The right one had some surface rust but came apart in a single hit, figure that out?! I got a local garage to press the new wheel bearings in, reassemble was the opposite and didn't take long at all. Removing the hub itself was simple. Starting with removing the brake caliper, 2x 14mm bolts for the caliper slider and 2x 19mm? for the carrier > hub bolts. I used a cable tie to secure the caliper to the upper arm so it was out of the way, there's a 10mm bolt securing the ABS sensor on. With the brake disc removed from the hub next are the three castle nuts for the upper and lower ball joints and track rod end. Two of these had their own R clip and one split pin. A few hits with the hammer and they're released (I left the castle nuts on by a couple of turns), the track rod ends gave me the most grief and I may have nipped the boots (oops). Fitting is the reversal and is very quick and easy to do. The lower ball joints are held onto the hub by 2x 17mm bolts. The castle nut did increase in socket size to 22mm from memory (this may vary from supplier) The two front tyres weren't in great condition, so I had those replaced with some budget tyres for the time being. I'll be replacing the wheels and tyres in the future, this was to get me on the road without the worry of the police hassling me.
    • Haggerty
      RB25DE NEO with Haltech ECU

      By Haggerty · Posted

      Yep, the closest base tune available was for the GTT, I went with that and made all the logical changes I could find to convert it to Naturally Aspirated. It will rev fine in Neutral to redline but it will be cutting nearly 50% fuel the whole way.  If I let it tune the fuel map to start with that much less fuel it wont run right and has a hard time applying corrections.  These 50% cuts are with a fuel map already about half of what the GTT tune had.  I was having a whole lot of bogging when applying any throttle but seem to have fixed that for no load situations with very aggressive transient throttle settings. I made the corrections to my injectors with data I found for them online, FBCJC100 flowing 306cc.  I'll have to look to see if I can find the Cam section. I have the Bosch 4.9 from Haltech. My manifold pressure when watching it live is always in -5.9 psi/inHg
    • brillo
      Leak from Tokico BM50 Brake Master Cylinder

      By brillo · Posted

      Hi My Tokico BM50 Brake master cylinder has a leak from the hole between the two outlets (M10x1) for brake pipes, I have attached a photo. Can anyone tell me what that hole is and what has failed to allow brake fluid to escape from it, I have looked on line and asked questions on UK forums but can not find the answer, if anyone can enlighten me I would be most grateful.
    • MBS206
      Cas issue

      By MBS206 · Posted

      It will be a software setting. I don't believe many on here ever used AEM. And they're now a discontinued product,that's really hard to find any easy answers on. If it were Link or Haltech, someone would be able to just send you a ECU file though.
×
×
  • Create New...