Hey All New Intake... odd idle tho...???

[NoMotive]

Well i just installed a Stillen Intake (took 4ever to deliver) BTW don't ever use FedEx... I live 20 minutes away from Stillen's HQ in Costa Mesa and FedEx misdelivered it to SACRAMENTO!!! Anyways, at full throttle the intake roars smoothly, but im noticing that at idle the needle keeps fluctuating between 7 to 9 hundred RPMs. Whenever the needle drops to around 7, i'll hear a very low bass-like thoom, and the needle kicks back up slightly. With the engine running, i hear a mild throom, throom sound coming in waves. Hard to describe in words other than that the J30 powers nicely in the upper RPM band now. If this sound should be something of concern lemme know! Lates.

[doesn't know jack]

mine ('94) does the same thing... I just got it two months ago, and I don't think the intake has been replaced, but the fluxuation at idle is the same... unfortunately I don't know what causes it. sorry.

[Nahkapohjola]

Maxima J30 VG30E:
- poor idle main sources:
0. Air filter
1. ignition wirings, spark plugs, distr cap [worn =old -replace every 60.000miles]
2. TPS Throttle pos sensor [even new ones! -replace -90$]
3. Carbon particles in idle adjustment steppermotor valves, throttle assy. [open, clean every 60.000miles]
4. Brittled ctrl tubing ends =leaks [ take our everyone, cut 1/4" off from ends, put back.]
5. Wiring oxidation. [Take all wiring connectors off, clean. In each connector put minuscle drop of connector grease.]

[Infinity300zx]

I got a stock j30 93 and at idle mine fluxes a little i think its just changing speeds due to fan belt alternater ect. and when you change the intake the air flow is different, so maybe that makes the low bass sound???? I dunno maybe a new ecu would compinsate the flow better.

[Nahkapohjola]

If all is ok, idle is stable.

Possible reasons: TPS Throttle pos sensor - change.
Carbon buildup in idle adj stepper motor assy, throttle - open &clean every 60.000.

[Va5h]

i had the same problem whith my J30 (BTW J30's Rule) and i know the solution. it is gunk built up in the fule filter. if you take the fule filter off you should be abel to blow threw it whith no restriction at all (use a rag to blow threw so you dont inhale gassoline + there are arrows on the filter showing witch way the fule goes so blow that way) if there is any restriction then replace it. you have fule going threw it at like 30 P.S.I. so it still gets threw and the car runs. when restricted you get that problem. if it is ok and is clean the do what the other posts say.