Intermittent Slight Stumble at Idle

Jordo! · 04-13-2012, 08:09 PM

Battery is fine.

No intake leaks (replaced a damaged breather, which I thought was the cause, and tightened all hose clamps).

May or may not be more prone to do when A/C running.

Air filters have less than 10K on them.

Any ideas?

I'm down to trying to clean the MAF sensors (I have proper spay cleaner) or maybe having my accessory belt checked for some slip (but under 35K on car...), but both seem unlikely to me...

Jordo! · 04-14-2012, 07:45 PM

Nobody?

Well, I re-tightened all clamps when engine was cold, cleaned some debris out of the airboxes, and seems happier. Belt is fine and tension is good.

Guess if it acts up again I'll try cleaning the MAFS.

If anyone has another suggestion, let me know.

370ZilverZ · 04-14-2012, 09:32 PM

My hesitation problems all went away after my UpRev tune.

Jordo! · 04-14-2012, 10:29 PM

Quote:

Originally Posted by 370ZilverZ

My hesitation problems all went away after my UpRev tune.

It's not a hesitation under acceleration.

At idle, in gear it will suddenly drop to about 500 RPM and then go back to 700ish.

370ZilverZ · 04-14-2012, 10:34 PM

That sounds like vacuum. What had you done prior to this starting?

theDreamer · 04-14-2012, 10:35 PM

My car has done this before, never did figure out what it is.
Though I thought mine might be caused from my SC and tuning, usually mine occurs if I am idle for longer than 60 seconds.

Dark Sarcasm · 04-14-2012, 10:56 PM

cars nowadays are tuned from the factory to idle at just above stalling in an attempt to save fuel. a little studder in RPMs isnt anything to worry about. IMO

spearfish25 · 04-15-2012, 08:40 AM

I wouldn't worry about it. Mine occasionally does it, particularly on really warm summer days. It's never stalled, just a random stumble. 99.999% of the time she runs like a top, so I just ignore it.

m4a1mustang · 04-15-2012, 08:56 AM

I wouldn't worry about it. The S2000 and the beast do it too. It's most prominent on a warmer day with the A/C on.

6MT · 04-15-2012, 01:27 PM

Quote:

Originally Posted by Jordo!

Battery is fine.

No intake leaks (replaced a damaged breather, which I thought was the cause, and tightened all hose clamps).

May or may not be more prone to do when A/C running.

Air filters have less than 10K on them.

Any ideas?

I'm down to trying to clean the MAF sensors (I have proper spay cleaner) or maybe having my accessory belt checked for some slip (but under 35K on car...), but both seem unlikely to me...

If yours is a manual gearbox, maybe you've got air in the system. Bleed the slave cylinder for air.

04-13-2012, 08:09 PM	#1 (permalink)
Jordo! A True Z Fanatic Join Date: May 2010 Location: nirvana Posts: 6,394 Drives: 2023 NATM Rep Power: 418	Intermittent Slight Stumble at Idle Battery is fine. No intake leaks (replaced a damaged breather, which I thought was the cause, and tightened all hose clamps). May or may not be more prone to do when A/C running. Air filters have less than 10K on them. Any ideas? I'm down to trying to clean the MAF sensors (I have proper spay cleaner) or maybe having my accessory belt checked for some slip (but under 35K on car...), but both seem unlikely to me... __________________ Enjoy it. Destroy it.

04-14-2012, 07:45 PM	#2 (permalink)
Jordo! A True Z Fanatic Join Date: May 2010 Location: nirvana Posts: 6,394 Drives: 2023 NATM Rep Power: 418	Nobody? Well, I re-tightened all clamps when engine was cold, cleaned some debris out of the airboxes, and seems happier. Belt is fine and tension is good. Guess if it acts up again I'll try cleaning the MAFS. If anyone has another suggestion, let me know. __________________ Enjoy it. Destroy it.

04-14-2012, 09:32 PM	#3 (permalink)
370ZilverZ A True Z Fanatic Join Date: Dec 2011 Location: DFW, TX Age: 67 Posts: 2,321 Drives: '11 BMW Z4 Rep Power: 19	My hesitation problems all went away after my UpRev tune. __________________ 370ZilverZ Journal BMW Z4

04-14-2012, 10:34 PM	#5 (permalink)
370ZilverZ A True Z Fanatic Join Date: Dec 2011 Location: DFW, TX Age: 67 Posts: 2,321 Drives: '11 BMW Z4 Rep Power: 19	That sounds like vacuum. What had you done prior to this starting? __________________ 370ZilverZ Journal BMW Z4

04-14-2012, 10:35 PM	#6 (permalink)
theDreamer A True Z Fanatic Join Date: Feb 2009 Location: Texas Posts: 30,879 Drives: 370z Rep Power: 4210	My car has done this before, never did figure out what it is. Though I thought mine might be caused from my SC and tuning, usually mine occurs if I am idle for longer than 60 seconds. __________________ theDreamer's Z // Fast Intentions // Uprev // GTM // HKS // TEIN theDreamer's Silvia // URAS // GREDDY Houston Zs // Facebook // Twitter // Instagram

04-14-2012, 10:56 PM	#7 (permalink)
Dark Sarcasm Track Member Join Date: Dec 2010 Location: Katy Texas Posts: 552 Drives: 11 CTS-V Coupe Rep Power: 16	cars nowadays are tuned from the factory to idle at just above stalling in an attempt to save fuel. a little studder in RPMs isnt anything to worry about. IMO __________________ wax

04-15-2012, 08:40 AM	#8 (permalink)
spearfish25 A True Z Fanatic Join Date: Mar 2009 Location: Naples, FL Posts: 4,117 Drives: to work Rep Power: 1856	I wouldn't worry about it. Mine occasionally does it, particularly on really warm summer days. It's never stalled, just a random stumble. 99.999% of the time she runs like a top, so I just ignore it. __________________ 2013 Cadillac V-Wagon, RIP Z

04-15-2012, 08:56 AM	#9 (permalink)
m4a1mustang A True Z Fanatic Join Date: Feb 2009 Location: Northern VA Posts: 55,385 Drives: on two wheels Rep Power: 6962	I wouldn't worry about it. The S2000 and the beast do it too. It's most prominent on a warmer day with the A/C on. __________________ - Steve Zs & Coffee - Saturdays at 10AM in Fairfax, VA and Columbia, MD (Click the banner!) LIKE us on Facebook!

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