Rough Idle JB4

J_Vang · 03-02-2015, 08:54 PM

Mods:

-JB4
-VRSF Downpipe
-Map 5
-AFE Magnum Intake

At a standstill it sounds like it might be bouncing up and down a few hundred rpms but the gauge doesn't flinch. Anyone else experience this? This happened after I installed the VRSF downpipe. BMS recommended I turn it off to map zero and see if that addresses the issue. Will report back later.

UPDATE:

https://www.youtube.com/watch?v=Kgknb8ZjHyA

mike@x-ph.com · 03-03-2015, 12:25 PM

your title says rough idle and the explanation says boucing rpm which are 2 different things
Bouncing RPM at cold start is normal.
If you are experiencing a rough idle i would check spark plugs, ignition coils and injectors
When a rough idle is happening on cold start only it is probably a bad injector

J_Vang · 03-12-2015, 11:29 AM

updated with video

J_Vang · 03-25-2015, 12:36 PM

Bummer, nobody has this strange idle?

FC4 · 03-25-2015, 07:13 PM

Quote:

Originally Posted by J_Vang

Bummer, nobody has this strange idle?

Nope.

harkes · 03-25-2015, 08:05 PM

Is it periodic or not? I have experienced something similar - also without the JB4 installed. I think its just harder for the car to get the AFR spot on without the original downpipe - hence it fluctuates more on the AFR. You can easily see it using e.g. the Torque app.

J_Vang · 03-25-2015, 08:27 PM

I'll have to try the torque app. It's always consistent in its moaning/whining like idle. It comes on after the cold start and quiets down significantly if the a/c is off.

TriniJots · 03-25-2015, 10:42 PM

Quote:

Originally Posted by mike@x-ph.com

your title says rough idle and the explanation says boucing rpm which are 2 different things
Bouncing RPM at cold start is normal.
If you are experiencing a rough idle i would check spark plugs, ignition coils and injectors
When a rough idle is happening on cold start only it is probably a bad injector

+1
This is most likely what the problem is

Earthmaster · 03-26-2015, 09:19 AM

Same issue but had it with Stage 1 and intake. Still comes and goes with the JB4 now that I have installed. On cold starts sometimes it rumbles a bit for 30 seconds and then chills out.

DasboostF80 · 03-26-2015, 09:29 AM

Have you tried uninstalling the entire jb4? I would pull it all out clean the connectors and reinstall. That would be the easiest process to chase this down.

Mean E92 · 07-06-2016, 01:44 AM

I know that this is a major grave dig but I could not seem to find another thread about this issue. I have the same issue after installing the VRSF catless dp and JB4 Stage 2. Have you found a solution?

CRJdriver · 07-07-2016, 10:03 AM

unplug maf, let the wideband and jb4 handle idle. mafless is supported.

OP probably has a leak in the intake between the maf and inlet since afe intake was mention. Do a throttle adaptation reset while your at it. Might idle like crap at first while it relearns. If problem still exist then it's the o2 sensor.

Mike@N54Tuning.com · 07-07-2016, 05:54 PM

Quote:

Originally Posted by Mad E92

I know that this is a major grave dig but I could not seem to find another thread about this issue. I have the same issue after installing the VRSF catless dp and JB4 Stage 2. Have you found a solution?

Are those your only mods?

Mike

Mean E92 · 07-08-2016, 01:37 PM

Quote:

Originally Posted by Mike@N54Tuning.com

Are those your only mods?

Mike

Yes, they are. I'm installing a chargepipe and a BMS intake today.

Mean E92 · 07-28-2016, 10:32 PM

Quote:

Originally Posted by Mike@N54Tuning.com

Are those your only mods?

Mike

So Mike, no other suggestion then checking plugs and coils right?

Mean E92 · 07-29-2016, 04:41 PM

I wish the OP was still active on his account :/

mxrider3355 · 09-04-2016, 08:27 PM

and am taking it in to bmw specialist to diagnose... same parts (JB4, map 2, catless downpipes, intake, and chargepipe) did anyone ever find a solution?

serr · 02-03-2017, 04:11 AM

If I have a JB4 installed and then I update my Ecu with winkfp,I will lose the map of JB4???

Mike@N54Tuning.com · 02-03-2017, 09:22 AM

Quote:

Originally Posted by serr

If I have a JB4 installed and then I update my Ecu with winkfp,I will lose the map of JB4???

No the JB4 is a standalone module.. It is not affected by any BMW ECU/DME updates.

Mike

serr · 02-03-2017, 10:06 AM

I bought a 730d and I did every possible thing,like updates,checking sensors. But still, the boost and MAF actual values are much higher than the targeted values and high consumtion and a lot of power.. If there is a standalone box,where would it be? How could I find it?
I just want my car to be in the factory specs.

03-02-2015, 08:54 PM	#1
J_Vang Private First Class 13 Rep 168 Posts Drives: 14 F30 335i M Sport Join Date: May 2013 Location: Atlanta iTrader: (1)	Rough Idle JB4 Mods: -JB4 -VRSF Downpipe -Map 5 -AFE Magnum Intake At a standstill it sounds like it might be bouncing up and down a few hundred rpms but the gauge doesn't flinch. Anyone else experience this? This happened after I installed the VRSF downpipe. BMS recommended I turn it off to map zero and see if that addresses the issue. Will report back later. UPDATE: https://www.youtube.com/watch?v=Kgknb8ZjHyA Last edited by J_Vang; 03-13-2015 at 08:34 AM..
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03-03-2015, 12:25 PM	#2
mike@x-ph.com BimmerPost Supporting Vendor 24183 Rep 190,777 Posts Drives: 07-335/12-328/18-M4/21-M4CP Join Date: Sep 2013 Location: Las Vegas iTrader: (23)	your title says rough idle and the explanation says boucing rpm which are 2 different things Bouncing RPM at cold start is normal. If you are experiencing a rough idle i would check spark plugs, ignition coils and injectors When a rough idle is happening on cold start only it is probably a bad injector __________________ Check out our current sale by clicking on this link! https://x-ph.com/sale/ Phone number 702-494-9435
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03-12-2015, 11:29 AM	#3
J_Vang Private First Class 13 Rep 168 Posts Drives: 14 F30 335i M Sport Join Date: May 2013 Location: Atlanta iTrader: (1)	updated with video
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03-25-2015, 12:36 PM	#4
J_Vang Private First Class 13 Rep 168 Posts Drives: 14 F30 335i M Sport Join Date: May 2013 Location: Atlanta iTrader: (1)	Bummer, nobody has this strange idle?
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03-25-2015, 08:05 PM	#6
harkes Colonel 1078 Rep 2,357 Posts Drives: M135i, E39 M5, NSX and AE86 Join Date: Apr 2014 Location: Xiamen, China iTrader: (0)	Is it periodic or not? I have experienced something similar - also without the JB4 installed. I think its just harder for the car to get the AFR spot on without the original downpipe - hence it fluctuates more on the AFR. You can easily see it using e.g. the Torque app. __________________ M135i 8AT PWG, MHD, Pure Stage2, WMI via Torqbyte CM5-LT, Custom tuned by PureBoost (A Dane in China)
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03-25-2015, 08:27 PM	#7
J_Vang Private First Class 13 Rep 168 Posts Drives: 14 F30 335i M Sport Join Date: May 2013 Location: Atlanta iTrader: (1)	I'll have to try the torque app. It's always consistent in its moaning/whining like idle. It comes on after the cold start and quiets down significantly if the a/c is off.
	Appreciate 0 Quote

03-26-2015, 09:19 AM	#9
Earthmaster Captain 127 Rep 851 Posts Drives: 15' M4 Austin Yellow Join Date: Sep 2014 Location: GTA iTrader: (3)	Same issue but had it with Stage 1 and intake. Still comes and goes with the JB4 now that I have installed. On cold starts sometimes it rumbles a bit for 30 seconds and then chills out.
	Appreciate 0 Quote

03-26-2015, 09:29 AM	#10
DasboostF80 Private First Class 244 Rep 194 Posts Drives: 2023 Marina Bay X3M Comp Join Date: Mar 2015 Location: Wilmington, Nc iTrader: (0)	Have you tried uninstalling the entire jb4? I would pull it all out clean the connectors and reinstall. That would be the easiest process to chase this down.
	Appreciate 0 Quote

07-06-2016, 01:44 AM	#11
Mean E92 Private First Class 40 Rep 177 Posts Drives: 2011 BMW E92 335i Join Date: Jun 2016 Location: San Francisco, California iTrader: (0)	I know that this is a major grave dig but I could not seem to find another thread about this issue. I have the same issue after installing the VRSF catless dp and JB4 Stage 2. Have you found a solution?
	Appreciate 0 Quote

07-07-2016, 10:03 AM	#12
CRJdriver Second Lieutenant 82 Rep 253 Posts Drives: F30 & F82 Join Date: Mar 2016 Location: LA iTrader: (0)	unplug maf, let the wideband and jb4 handle idle. mafless is supported. OP probably has a leak in the intake between the maf and inlet since afe intake was mention. Do a throttle adaptation reset while your at it. Might idle like crap at first while it relearns. If problem still exist then it's the o2 sensor.
	Appreciate 0 Quote

07-29-2016, 04:41 PM	#16
Mean E92 Private First Class 40 Rep 177 Posts Drives: 2011 BMW E92 335i Join Date: Jun 2016 Location: San Francisco, California iTrader: (0)	I wish the OP was still active on his account :/
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09-04-2016, 08:27 PM	#17
mxrider3355 New Member 8 Rep 28 Posts Drives: Now: 2013 335i Had: 2006 3251 Join Date: Dec 2008 Location: Northern NJ iTrader: (0)	have same problem and am taking it in to bmw specialist to diagnose... same parts (JB4, map 2, catless downpipes, intake, and chargepipe) did anyone ever find a solution?
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02-03-2017, 04:11 AM	#18
serr New Member 0 Rep 12 Posts Drives: e90 Join Date: Jan 2017 Location: romania iTrader: (0)	If I have a JB4 installed and then I update my Ecu with winkfp,I will lose the map of JB4???
	Appreciate 0 Quote

02-03-2017, 10:06 AM	#20
serr New Member 0 Rep 12 Posts Drives: e90 Join Date: Jan 2017 Location: romania iTrader: (0)	I bought a 730d and I did every possible thing,like updates,checking sensors. But still, the boost and MAF actual values are much higher than the targeted values and high consumtion and a lot of power.. If there is a standalone box,where would it be? How could I find it? I just want my car to be in the factory specs. Attached Images
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