Engine Stalls on first cold start

Dynamics99 · 07-02-2021, 10:16 PM

The car sits in the garage and on a cold start it starts up and 90% of the time it stalls/dies. The second start gets it working. If I give it gas on the first start then the RPMs kinda stay but it seems to bog sometimes. Replaced CCV a while ago with an aftermarket kit. Replaced starter with aftermarket also. In addition to the valve cover, OFHG, and oil change. Could it be that there is a vacuum leak or the starter is starting the engine too fast? Have the M54B30.

GuidoK · 07-02-2021, 10:57 PM

Without obd diagnose the engine:
vacuum leak could explain this.
The rubber intake boots are prone to tears as they get older.
#4 and #5 in next link:
http://bmwfans.info/parts-catalog/E8...ir_mass_meter/

But if you want to know more, a simple obd2 dongle (available under $5 delivered I believe...) and a free version of torque (or a similar app/program) could tell so much more.
Or of course an INPA interface (about $15-$20 I believe).

VitaeCursos · 07-05-2021, 11:57 PM

First, do you have a check engine light or "Service engine soon" light on? If so stop by an auto parts store and ask them to pull the codes for you and let us know what they are.

If a car is starting, there's no problem with the starter motor. My guess based on what you report is that you might have a leak back issue with the fuel pump. Try turning the key to the on position a couple of times before trying to start the car next time you do a cold start. If that helps it start normally it means that the check valve in the fuel pump isn't working correctly and it's allowing fuel to drain back into the tank forcing the pump to prime the system every time. That's just a guess though; having those codes would be of great help.

GuidoK · 07-06-2021, 02:18 AM

Quote:

Originally Posted by VitaeCursos

it's allowing fuel to drain back into the tank forcing the pump to prime the system every time. That's just a guess though; having those codes would be of great help.

This is afaik really rare on the z4 fuel pump.
I think it would also be difficult to diagnose with OBD (I don't think there's a fuel pressure sensor, so a lean code is the only thing to go on, but a vacuum leak would give the same error), but a pressure gauge on the bleed valve on the fuel rail is an option I think.

Dynamics99 · 07-15-2021, 03:41 PM

Hi All,

I have used INPA before on an old computer using the bimmergeeks tool version. I now have a different laptop and installed INPA. The main menu is in english but when I select the E85 chasis and go to select the MS45.0 m54 for Engine the menu translates to german. I checked my ini and it was set to English for Variante and Englisch for Enviorn.

Is there an install issue?

Dynamics99 · 07-17-2021, 09:12 AM

I pulled up the fault codes.

Seems none of these could relate to the cold start stall/bogging.

HBC · 08-01-2021, 07:48 PM

Mine has the drop in rpms on a cold start as well but it doesn't stall. It's done this since I've owned it.

chickdr · 08-01-2021, 08:15 PM

Quote:

Originally Posted by HBC

Mine has the drop in rpms on a cold start as well but it doesn't stall. It's done this since I've owned it.

Mine does the same. Always drops after starting, but doesn't stall.

bobmole · 08-02-2021, 08:26 AM

This may be all wrong, but mine drops RPMs after start occasionally and runs a little rough. Dealership said ignition coils need replacing. Not that big of a deal, so I passed. Problem intermittent.

zorro2252 · 10-25-2021, 09:48 AM

OP, did you find the fault? I had this issue on a 2004 3.0i Z4 I bought last month- cleaning out the IACV (idle air control valve) with an alcohol based cleaner completely eliminated the rough, stall-y cold starts. I have a warranty through the dealership I bought it from and they misdiagnosed it as an ignition issue & replaced the whole set of spark plugs & coil packs.

Would be worth checking your lower intake hose for tears while you're in there, since you have to take it out to get the the IACV. The lower hose perishes over time and splits quite easily thanks to all of the connections coming off it- I found two great big tears in the small diameter piece branching off to the IACV which were allowing non-metered air into the valve.

07-02-2021, 10:16 PM	#1
Dynamics99 Private First Class 28 Rep 161 Posts Drives: 2011 E92 & E90 335i 6MT MSport Join Date: Oct 2019 Location: Philadelphia iTrader: (0)	Engine Stalls on first cold start The car sits in the garage and on a cold start it starts up and 90% of the time it stalls/dies. The second start gets it working. If I give it gas on the first start then the RPMs kinda stay but it seems to bog sometimes. Replaced CCV a while ago with an aftermarket kit. Replaced starter with aftermarket also. In addition to the valve cover, OFHG, and oil change. Could it be that there is a vacuum leak or the starter is starting the engine too fast? Have the M54B30.
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07-02-2021, 10:57 PM	#2
GuidoK #buildnotbought 10852 Rep 4,892 Posts Drives: Z4 3.0i ESS TS2+ Join Date: Jul 2012 Location: Tinkering in the garage iTrader: (0)	Without obd diagnose the engine: vacuum leak could explain this. The rubber intake boots are prone to tears as they get older. #4 and #5 in next link: http://bmwfans.info/parts-catalog/E8...ir_mass_meter/ But if you want to know more, a simple obd2 dongle (available under $5 delivered I believe...) and a free version of torque (or a similar app/program) could tell so much more. Or of course an INPA interface (about $15-$20 I believe). __________________ Z4 3.0i \| ESS TS2+ supercharger \| Quaife ATB LSD \| Brembo/BMW performance BBK front/rear \| Schrick FI cams \| Schmiedmann headers+cats \| Powerflex/strongflex PU bushings \| Vibra-technics engine mounts \| H&R anti rollbars \| KW V3 coilovers/KW camber plates \| Sachs race engineering clutch \| tons of custom sh#t Last edited by GuidoK; 07-02-2021 at 11:14 PM..
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07-05-2021, 11:57 PM	#3
VitaeCursos Registered 2 Rep 2 Posts Drives: 03 Z4i Join Date: Jul 2021 Location: Englewood, CO iTrader: (0)	First, do you have a check engine light or "Service engine soon" light on? If so stop by an auto parts store and ask them to pull the codes for you and let us know what they are. If a car is starting, there's no problem with the starter motor. My guess based on what you report is that you might have a leak back issue with the fuel pump. Try turning the key to the on position a couple of times before trying to start the car next time you do a cold start. If that helps it start normally it means that the check valve in the fuel pump isn't working correctly and it's allowing fuel to drain back into the tank forcing the pump to prime the system every time. That's just a guess though; having those codes would be of great help.
	Appreciate 0 Quote

07-17-2021, 09:12 AM	#6
Dynamics99 Private First Class 28 Rep 161 Posts Drives: 2011 E92 & E90 335i 6MT MSport Join Date: Oct 2019 Location: Philadelphia iTrader: (0)	I pulled up the fault codes. Seems none of these could relate to the cold start stall/bogging.
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08-01-2021, 07:48 PM	#7
HBC Private 124 Rep 57 Posts Drives: 2006 Z4M Join Date: Jun 2020 Location: Ontario iTrader: (1)	Mine has the drop in rpms on a cold start as well but it doesn't stall. It's done this since I've owned it.
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07-15-2021, 03:41 PM	#5
Dynamics99 Private First Class 28 Rep 161 Posts Drives: 2011 E92 & E90 335i 6MT MSport Join Date: Oct 2019 Location: Philadelphia iTrader: (0)	Hi All, I have used INPA before on an old computer using the bimmergeeks tool version. I now have a different laptop and installed INPA. The main menu is in english but when I select the E85 chasis and go to select the MS45.0 m54 for Engine the menu translates to german. I checked my ini and it was set to English for Variante and Englisch for Enviorn. Is there an install issue?
	Appreciate 0 Quote

08-02-2021, 08:26 AM	#9
bobmole Registered 0 Rep 3 Posts Drives: 2006 z4Si Join Date: Feb 2015 Location: Colorado iTrader: (0)	This may be all wrong, but mine drops RPMs after start occasionally and runs a little rough. Dealership said ignition coils need replacing. Not that big of a deal, so I passed. Problem intermittent.
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10-25-2021, 09:48 AM	#10
zorro2252 Registered 0 Rep 1 Posts Drives: BMW E85 Z4 3.0i Join Date: Oct 2021 Location: United Kingdom iTrader: (0)	OP, did you find the fault? I had this issue on a 2004 3.0i Z4 I bought last month- cleaning out the IACV (idle air control valve) with an alcohol based cleaner completely eliminated the rough, stall-y cold starts. I have a warranty through the dealership I bought it from and they misdiagnosed it as an ignition issue & replaced the whole set of spark plugs & coil packs. Would be worth checking your lower intake hose for tears while you're in there, since you have to take it out to get the the IACV. The lower hose perishes over time and splits quite easily thanks to all of the connections coming off it- I found two great big tears in the small diameter piece branching off to the IACV which were allowing non-metered air into the valve.
	Appreciate 0 Quote