Jerking between 3000-4000rpm. HELP !

[Advan_01]

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.

[predator]

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.

[QuickR33Melb]

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

[predator]

checking simple things is free..

[skygt]

Had the problem too and still have it.Checked all the hoses plugs, taking it in tomorrow hopefully gets fixed!!!

[QuickR33Melb]

where are you taking it

[skygt]

taking it to MSA imports dont know if you guys have any feedback on them,they have been ok till now.

[superspit]

how do you find the time to jerk between shifts..?

Good advice from the guys above.....not this one!

[Advan_01]

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?

[SKYNUTS]

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?

[R32PIMP]

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

[aybee]

i know of a car that just had this fixed and it was the coils.