Little issue at idle..

pty370z · 10-04-2010, 03:08 PM

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...

Cell · 10-04-2010, 03:17 PM

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.

spearfish25 · 10-04-2010, 05:39 PM

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).

GonGo · 10-04-2010, 07:29 PM

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.

Pharmacist · 10-05-2010, 06:08 PM

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.

m4a1mustang · 10-05-2010, 06:16 PM

Quote:

Originally Posted by Pharmacist

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.

Chan Chee Hoe · 10-05-2010, 06:38 PM

Quote:

Originally Posted by Pharmacist

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.

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.

spearfish25 · 10-05-2010, 08:43 PM

Quote:

Originally Posted by Chan Chee Hoe

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.

pty370z · 10-06-2010, 12:37 PM

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

Chan Chee Hoe · 10-07-2010, 05:33 AM

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.!

NewlyIMPORTed · 10-07-2010, 11:55 AM

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.

6MT · 10-07-2010, 11:59 AM

Quote:

Originally Posted by Chan Chee Hoe

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.

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.

Montez · 10-07-2010, 02:07 PM

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

kenchan · 10-08-2010, 11:30 AM

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

billydsz · 10-08-2010, 12:21 PM

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?

10-04-2010, 03:08 PM	#1 (permalink)
pty370z Track Member Join Date: Apr 2009 Location: Panama City, Panama Posts: 654 Drives: over the speed limit Rep Power: 18	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... sunjian_auto and fitxpert like this. __________________ 2010 Solid Red 370Z * *Touring-Sport-6MT Black Interior Performance:** STILLEN * BERK * UR * MISHIMOTO * K&N * Z1 * ZSPEED * UPREV * DBA Interior: GT-R Red Start/Stop Button * MSA Floor Mats * PW:JDM Exterior: INGS+1 * SEIBON * FUJIMURA * PW:JDM * UAM * KICS * VOLK Last edited by pty370z; 10-04-2010 at 03:10 PM.

10-04-2010, 05:39 PM	#3 (permalink)
spearfish25 A True Z Fanatic Join Date: Mar 2009 Location: Naples, FL Posts: 4,117 Drives: to work Rep Power: 1857	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). __________________ 2013 Cadillac V-Wagon, RIP Z

10-05-2010, 06:08 PM	#5 (permalink)
Pharmacist A True Z Fanatic Join Date: May 2009 Location: Toronto, Ontario Posts: 1,249 Drives: 09 370z Sport 6MT Rep Power: 19	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. __________________ 2009 370z Sport Touring/Nismo shift Knob/Z1 motorsports 34 row oil cooler

10-06-2010, 12:37 PM	#9 (permalink)
pty370z Track Member Join Date: Apr 2009 Location: Panama City, Panama Posts: 654 Drives: over the speed limit Rep Power: 18	It happens whether the A/C is on or off.. The effect is less noticeable with the A/C off but it still happens... __________________ 2010 Solid Red 370Z * *Touring-Sport-6MT Black Interior Performance:** STILLEN * BERK * UR * MISHIMOTO * K&N * Z1 * ZSPEED * UPREV * DBA Interior: GT-R Red Start/Stop Button * MSA Floor Mats * PW:JDM Exterior: INGS+1 * SEIBON * FUJIMURA * PW:JDM * UAM * KICS * VOLK

10-07-2010, 11:55 AM	#11 (permalink)
NewlyIMPORTed A True Z Fanatic Join Date: May 2009 Location: Kennesaw, GA Posts: 1,109 Drives: 11 STI Sedan Rep Power: 19	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. __________________ 2011 WRX STICobb Accessport, Nameless Performance exhaust, COBB SF Intake, COBB downpipe, 20% tint, Work Emotion XD9's

10-04-2010, 03:17 PM	#2 (permalink)
Cell A True Z Fanatic Join Date: Jan 2010 Location: Chicago Posts: 1,449 Drives: A Garbage Truck Rep Power: 22	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.

10-04-2010, 07:29 PM	#4 (permalink)
GonGo Base Member Join Date: Mar 2009 Location: Puerto Rico Posts: 80 Drives: 2009 370z PW M6 Rep Power: 17	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.

10-07-2010, 05:33 AM	#10 (permalink)
Chan Chee Hoe Track Member Join Date: Mar 2009 Location: Singapore Posts: 861 Drives: 370z,Yellow,7sp A Rep Power: 18	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.!

10-07-2010, 02:07 PM	#13 (permalink)
Montez Track Member Join Date: Sep 2009 Location: Manhattan Beach, Ca Posts: 604 Drives: 16 LEX GS,09 Z,03Max Rep Power: 17	Mine does this as well sometimes as well as the Max......Never had any major issues as a result.

10-08-2010, 11:30 AM	#14 (permalink)
kenchan A True Z Fanatic Join Date: Aug 2009 Location: N/A Posts: 76,801 Drives: N/A Rep Power: 141521	Was watching the tach but mine is solid at 700rpm or so. Even with AC running it doesn't affect too much. Temp 65F.

10-08-2010, 12:21 PM	#15 (permalink)
billydsz Enthusiast Member Join Date: Aug 2009 Location: New Bern Posts: 252 Drives: 9 370z SptCp SRd 7AT Rep Power: 16	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?

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