Little issue at idle..
 

Hi guys,

Just wanted to post this thing that's been happening for a little while and not really sure what could it be...

I have a 6MT w/sport package 370Z.. I have bolt-on mods like Stillen CBE, Berk HFCs, Stillen Gen3 Intakes, Stillen standard pulley...

The thing is, I've noticed that when I'm driving around, as soon as I stop, for example at a red light, and the car is idling, engine RPMs are steady usually at 750rpm, but for a fraction of a second they drop a little below 500rpm giving the feeling that the car is going to shutdown, and then the RPMs raise back up to normal idling... I can drive around for a while and whenever I stop it will happen again...

Any ideas on what may be causing this..?? Could this be a leak on the intakes or exhaust..??

I'll try to get it on video and post it up..

Any help appreciated...

Bad o2 sensor maybe? I dunno. I had that problem with my RSX too and it had a bad o2 sensor. I never fixed it. Traded it in and got the Nismo instead.

I notice it sometimes with my car as well. It's not frequent and I can't replicate it. Essentially as you described, it sometimes 'stutters' on the idle for a moment when coming to a stop. Fortunately, it's never died and doesn't do it often so I've ignored it. i don't think it's intake or exhaust related (I have stock intakes except for the COBB tubes, and it did it before the COBBs).

I'd guarantee your dealer would just shrug if you brought it in and told them about it. Or they'd try to make you pay for a $150 fuel injector cleaning. I think we have to wait until it's either frequently happening or keeps the engine from starting (hope it never comes to either of these).

I was just about to post about this same exact issue. my Car is completely stock and dips revs @ 500 or lower when I i stop. I have some Berk HFC's waiting to be installed but want to sort this out first.

is the AC on? Could it be the compressor clutch engaging and disengaging? Or maybe the radiator fan coming on and temporarily taking more electricity from the battery and weakening the ignition? Or maybe it's the electronic throttling system on the car, which does tend to be a bit sluggish and slow to respond.

Yeah, sometimes the AC can cause some hiccups in the engine's idle speed.

Cannot be the A/C compressor cutting in,because our engine is a 3.7v6[good torque in idling],not a 1L in line 4.

Not so sure about that reasoning. Our AC compressor really pulls on the motor. On a hot day, my idle will go from ~700 without AC up to about 900rpm with the AC running. Catch the Z off guard (if you will) and you go from 700rpm to 500rpm...a perceived hiccup.

That being said, I've had the low idle hiccup on hot days with the windows down and AC off.

It happens whether the A/C is on or off.. The effect is less noticeable with the A/C off but it still happens...

Anyway,when we modify the car,we expects the car idling to change,the best is stock if you want the best idling,i remember my friend's Subaru STI,he changes his cams,results is an engine as rough as a diesel at idle.!

see i have that problem too and when my ac is off it goes to 500 but when i turn it on it immediately revs itself back up.

I have to disagree with that. The A/C compressor IS a significant "drag" on the engine when the clutch engages it. It will affect the idle speed momentarily.

Mine does this as well sometimes as well as the Max......Never had any major issues as a result.

Was watching the tach but mine is solid at 700rpm or so. Even with AC running it doesn't affect too much. Temp 65F.

Mines steady as a rock ac or no ac. But I have the 7AT.... could it be the rev match on the 6mt possibly glitching?