Jump to content
SAU Community

Recommended Posts

Hi Guys, recently my car starts to jerk a little once it touches 3000rpm and stops at 4000rpm. This happens especially in the morning and also when say u are crusing at a constant speed and u step a bit more gas suddenly. Doesnt matter which gear u are on so long as it touches that range it will start to jerk a bit. If I were to do a launch, I realise there no jerking at all. Don't think its the boost cut because u don't have to put your foot down all the way to have the jerking. And it's not misfiring for sure coz I just changed my plugs and regapped to 0.8. My fuel pump works fine and injectors too I think, if not the jerking might be everywhere when I push the motor. Wondering if any of u guys had this problem before or any of u can help.

Link to comment
https://www.sau.com.au/forums/topic/41210-jerking-between-3000-4000rpm-help/
Share on other sites

is it making a sort of stuttering noise? if so its probably a boost leak.. check all your major hoses and intake piping.

Had that problem in the past myself. Ok at light throttle, but soon as it got to a certain point the motor (or ECU working out the engine was lacking) would start playing funny buggers and stutter.

I've had this problem as well. I would be willing to bet you a slab of beer it's a bad plug or dirty coils. If your out north take it to these guys

J.P.C. Johnsons Performance Centre Pty Ltd

Turbo Reconditioning, Dyno Tuning, Hi Performance Turbo Charging

27 Lipton Drv Thomastown VIC 3074

ph: (03) 9469 2566 Motor Engineers & Repairers

$88 for a dyno and they will diagnose the problem exactly. Best money you will spend

My car just came back from the wrokshop. Problem solve...phewww! My cam sensor is faulty. Now it is back to normal. But my tuner actually lower my boost to 0.70 - 0.75 Bar and surprisingly I got a little kws on wheels gain comparing with what I boost before (0.95-1.0 bar). So theortically if I boost back to 0.95 - 1.0 Bar I get more rwkws? What do u guys reckon?

  • 5 weeks later...
I've had this problem as well.  I would be willing to bet you a slab of beer it's a bad plug or dirty coils.  If your out north take it to these guys

J.P.C. Johnsons Performance Centre Pty Ltd

Turbo Reconditioning, Dyno Tuning, Hi Performance Turbo Charging

27 Lipton Drv Thomastown VIC 3074

ph: (03) 9469 2566  Motor Engineers & Repairers

$88 for a dyno and they will diagnose the problem exactly.  Best money you will spend

i have the same problem , like someone tapping on yr brakes when u accelerate. It only started happening only after i had my fmic , pump , regulator and boost (0.9bar). I just changed my plugs with .8 gap so cant be plugs. is it really the coils?

Hard to say unless you drive the thing yourself. I had a similar problem between 4000 -5000. I tried so many things, including new platinum plugs, pulled out the injectors and had them cleaned and flow tested, new oxygen sensor blah blah blah....still happening.

I swapped my old pod filter for a spanking new K&N pod..... problem solved. Guess she wasn't sucking enough air. Some times it's the little things :D

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


  • Similar Content

  • Latest Posts

    • Well it wasn't as easy as I thought.... and it also wasn't in my original manual which I did end up finding. They discuss the process in the Nismo catalogue though and it requires slight machining. Page 145.  NISMO PARTS CATALOGUE 2020
    • I'm an idiot, my intercooler is rated for 1000hp. I had clicked on the wrong product. Knowing the delta P would be nice, but I'm doubtful I'll do it. Now as for an EMAP, that would be great and I'll get around to it eventually but from my findings in my last post, I'm considering a turbo swap now. 
    • You sir, big win tonight. Precision never supplied compressor maps in the past and Idk when they started, but it seems they only offer for a few of the older gen2's which is exactly what I have. I punched in some numbers and seem to have gone with the wrong turbo. 600-700whp isn't in the most efficient area and is close to the choke line. 800whp is well off the map. Punching the numbers into a 68mm gen2 turbo map is bang on in the center. Here I was thinking going smaller would shift the power band down, but in reality it would just make it so much worst due to my rev limit. I would have never thought. 
    • Increasing overlap will bring the torque down earlier (and make your idle sound sick lol). Worth a shot (if you dyno time) to experience a bit (providing you are confident your valves won't kiss your pistons). Is to just take off 5 degrees across the boosted area of the map, and then retard the exhaust cam let's say, 3 degrees at a time and then overlay all the runs with VCT on all the way and VCT off as soon as you make positive pressure. Ideally you would have a total of 6x overlays to looks at 0 exhaust & VCT off once manifold pressure is +ve 0 exhaust & VCT on all the way -5 exhaust & VCT off once manifold pressure is +ve -5 exhaust & VCT on all the way -10 exhaust & VCT off once manifold pressure is +ve -10 exhaust & VCT on all the way Just leave your O2 wideband closed loop on for all of the boost area & RPM, and hopefully there isn't too much fuel correction needed and the Haltech is fast enough to compensate (I do this, then apply the correction to the main table). Getting that overlay data should give you a good indication of what to aim for.
    • So, my main limitation here is that the car does not have an oil pressure sensor by default, just a switch. As part of my tune I bought an oil pressure sensor upgrade so I now have access to oil pressure levels and logging rather than just the boolean behaviour of the switch but this means I need to use the tuning app to display this value. So, this rules out using any other app on the iPad. The app will also flash when pressure drops which is a nice feature. I have replaced the centre screen with an Android one, which is awesome for Android Auto, but I think it might be too far away and out of my line of sight. I might add some gauges to it this weekend and just see. I guess if its just temp and oil pressure I can make them massive! 🤣  
×
×
  • Create New...