What is causing this long crank (fuel pressure?)

ZachE90M3 · 08-29-2023, 01:43 PM

Hey guys,

This has been happening the last few days but only on the initial startup and if it sat overnight. If I stop the crank and try again it’ll start right away. For the first few minutes it feels like it has a hesitation but only if I rev the throttle really quick.

I replaced the fuel sending unit on the driver’s side a couple of months ago.

I’ll try to upload a video but for some reason I can’t upload one here.

ZachE90M3 · 08-29-2023, 01:46 PM

Here is the video as I upload it to YouTube 🙄

https://youtube.com/shorts/YJrLHFfnv...xW9DOS29HoNUZQ

RocketyMan · 08-29-2023, 11:13 PM

Did you replace anything else?

Did you replace the fuel pressure sensor yet?

ZachE90M3 · 08-30-2023, 08:51 AM

Quote:

Originally Posted by RocketyMan

Did you replace anything else?

Did you replace the fuel pressure sensor yet?

No, I haven’t replaced anything yet.

lonatic · 08-30-2023, 01:32 PM

Check fuel pressure sensor

ZachE90M3 · 08-30-2023, 05:16 PM

Quote:

Originally Posted by lonatic

Check fuel pressure sensor

How do I check it? Is it something I can do or does it need a specific tool?

yardbro · 08-30-2023, 06:58 PM

Quote:

Originally Posted by ZachE90M3

How do I check it? Is it something I can do or does it need a specific tool?

You would at least need access to a scan tool to verify what the sensor is reading in terms of fuel pressure. Either that or access to ISTA +

lonatic · 08-30-2023, 08:25 PM

Are you getting any codes?

ZachE90M3 · 08-30-2023, 09:29 PM

Quote:

Originally Posted by lonatic

Are you getting any codes?

Nope no codes at all and none pending either. It does seem to have a slight hesitation though when it finally starts, but only when I flick the throttle quick.

lonatic · 08-30-2023, 09:56 PM

How many miles on car? what year? When you swapped in a new sending unit did you ensure the connection to the fuel pump on the passenger side was secure? No holes on any of the lines driver side or passenger side?

ZachE90M3 · 08-30-2023, 10:13 PM

Quote:

Originally Posted by lonatic

How many miles on car? what year? When you swapped in a new sending unit did you ensure the connection to the fuel pump on the passenger side was secure? No holes on any of the lines driver side or passenger side?

It’s a 2008 with 156k miles. Yes, everything was tight and didn’t seem like there was any holes. I changed it like 2 months ago and this just started happening.

lonatic · 08-30-2023, 10:19 PM

Quote:

Originally Posted by ZachE90M3

It’s a 2008 with 156k miles. Yes, everything was tight and didn’t seem like there was any holes. I changed it like 2 months ago and this just started happening.

Why did you change the sending unit? and this started happening after you installed it?

ZachE90M3 · 08-30-2023, 10:35 PM

Quote:

Originally Posted by lonatic

Why did you change the sending unit? and this started happening after you installed it?

I changed it because it had a slight crack in the housing and was leaking fuel. I changed it 2 months ago though. This literally just started happening a couple of days ago.

lonatic · 08-31-2023, 10:03 PM

I would replace fuel pressure sensor if you don't have access to reading fuel pressure.

ZachE90M3 · 09-01-2023, 12:22 AM

Quote:

Originally Posted by lonatic

I would replace fuel pressure sensor if you don't have access to reading fuel pressure.

I had it checked and it isn’t holding pressure correctly. When I rev it the pressure drops. Fuel pump is going bad. I ordered one. Sucks they cost like $500 🤦&zwj;♂️

spammysammich · 09-01-2023, 12:28 AM

How low is it dropping? it's normal for pressure in the rail to drop to some extent as the RPM increases and injector duty cycle goes up.

spammysammich · 09-01-2023, 12:31 AM

also, the fuel pressure sensor is WAY cheaper than the pump and is a known problem on these cars. Try that first since you'll eventually want to anyway.

lonatic · 09-01-2023, 12:37 AM

Quote:

Originally Posted by spammysammich

also, the fuel pressure sensor is WAY cheaper than the pump and is a known problem on these cars. Try that first since you'll eventually want to anyway.

Right on, plus 156k miles I’d do that first.

RocketyMan · 09-01-2023, 12:28 PM

Here is the updated fuel sensor from FCP: https://www.fcpeuro.com/products/bmw...kt#description

Is the updated one supposed to be "better" than the brass sensor? Anyone know more about this? Might be important if the OP decides to change this sensor out to help solve his issue.

ZachE90M3 · 09-01-2023, 12:48 PM

Quote:

Originally Posted by RocketyMan

Here is the updated fuel sensor from FCP: https://www.fcpeuro.com/products/bmw...kt#description

Is the updated one supposed to be "better" than the brass sensor? Anyone know more about this? Might be important if the OP decides to change this sensor out to help solve his issue.

I had it checked and appears that the pump is failing. It’s not able to supply the correct amount of pressure. I’ll report back if that doesn’t solve it though.

RocketyMan · 09-01-2023, 01:05 PM

Oh really? Wow...do you remember what brand pump you originally replaced it with? OEM? or..?

spammysammich · 09-01-2023, 01:40 PM

At that mileage you cannot rule out stuck or gummed up fuel injectors. They’re a known weak spot in S65/S85 motors.

08-29-2023, 01:43 PM	#1
ZachE90M3 Private First Class 148 Rep 184 Posts Drives: BMW M3 Join Date: May 2020 Location: USA iTrader: (0)	What is causing this long crank (fuel pressure?) Hey guys, This has been happening the last few days but only on the initial startup and if it sat overnight. If I stop the crank and try again it’ll start right away. For the first few minutes it feels like it has a hesitation but only if I rev the throttle really quick. I replaced the fuel sending unit on the driver’s side a couple of months ago. I’ll try to upload a video but for some reason I can’t upload one here.
	Appreciate 0 Tweet Quote

08-29-2023, 01:46 PM	#2
ZachE90M3 Private First Class 148 Rep 184 Posts Drives: BMW M3 Join Date: May 2020 Location: USA iTrader: (0)	Here is the video as I upload it to YouTube 🙄 https://youtube.com/shorts/YJrLHFfnv...xW9DOS29HoNUZQ
	Appreciate 0 Quote

08-29-2023, 11:13 PM	#3
RocketyMan Captain 772 Rep 883 Posts Drives: E53 X5, E83 X3, E93 M3 Join Date: Nov 2022 Location: PNW iTrader: (0) Garage List 2008 BMW M3 E93 [10.00]	Did you replace anything else? Did you replace the fuel pressure sensor yet? __________________ 2008 BMW M3 E93 MT, 3.15 FDR R135 └┼┼┼ ..246
	Appreciate 1 ZachE90M3148.00 Quote

08-30-2023, 01:32 PM	#5
lonatic Private First Class 31 Rep 115 Posts Drives: E90 M3, E36 M3 Join Date: Feb 2010 Location: NVA iTrader: (0)	Check fuel pressure sensor __________________ Alpine E90 M3 Dakar E36 M3
	Appreciate 1 ZachE90M3148.00 Quote

08-30-2023, 08:25 PM	#8
lonatic Private First Class 31 Rep 115 Posts Drives: E90 M3, E36 M3 Join Date: Feb 2010 Location: NVA iTrader: (0)	Are you getting any codes? __________________ Alpine E90 M3 Dakar E36 M3
	Appreciate 0 Quote

08-30-2023, 09:56 PM	#10
lonatic Private First Class 31 Rep 115 Posts Drives: E90 M3, E36 M3 Join Date: Feb 2010 Location: NVA iTrader: (0)	How many miles on car? what year? When you swapped in a new sending unit did you ensure the connection to the fuel pump on the passenger side was secure? No holes on any of the lines driver side or passenger side? __________________ Alpine E90 M3 Dakar E36 M3
	Appreciate 0 Quote

08-31-2023, 10:03 PM	#14
lonatic Private First Class 31 Rep 115 Posts Drives: E90 M3, E36 M3 Join Date: Feb 2010 Location: NVA iTrader: (0)	I would replace fuel pressure sensor if you don't have access to reading fuel pressure. __________________ Alpine E90 M3 Dakar E36 M3
	Appreciate 0 Quote

09-01-2023, 12:28 AM	#16
spammysammich Lieutenant Colonel 3073 Rep 1,799 Posts Drives: 2009 E92 M3 Dakar Yellow II Join Date: Oct 2021 Location: Edmonds, WA iTrader: (0) Garage List 2009 BMW M3 [10.00]	How low is it dropping? it's normal for pressure in the rail to drop to some extent as the RPM increases and injector duty cycle goes up.
	Appreciate 0 Quote

09-01-2023, 12:31 AM	#17
spammysammich Lieutenant Colonel 3073 Rep 1,799 Posts Drives: 2009 E92 M3 Dakar Yellow II Join Date: Oct 2021 Location: Edmonds, WA iTrader: (0) Garage List 2009 BMW M3 [10.00]	also, the fuel pressure sensor is WAY cheaper than the pump and is a known problem on these cars. Try that first since you'll eventually want to anyway.
	Appreciate 1 lonatic30.50 Quote

09-01-2023, 12:28 PM	#19
RocketyMan Captain 772 Rep 883 Posts Drives: E53 X5, E83 X3, E93 M3 Join Date: Nov 2022 Location: PNW iTrader: (0) Garage List 2008 BMW M3 E93 [10.00]	Here is the updated fuel sensor from FCP: https://www.fcpeuro.com/products/bmw...kt#description Is the updated one supposed to be "better" than the brass sensor? Anyone know more about this? Might be important if the OP decides to change this sensor out to help solve his issue. __________________ 2008 BMW M3 E93 MT, 3.15 FDR R135 └┼┼┼ ..246
	Appreciate 0 Quote

09-01-2023, 01:05 PM	#21
RocketyMan Captain 772 Rep 883 Posts Drives: E53 X5, E83 X3, E93 M3 Join Date: Nov 2022 Location: PNW iTrader: (0) Garage List 2008 BMW M3 E93 [10.00]	Oh really? Wow...do you remember what brand pump you originally replaced it with? OEM? or..? __________________ 2008 BMW M3 E93 MT, 3.15 FDR R135 └┼┼┼ ..246
	Appreciate 0 Quote

09-01-2023, 01:40 PM	#22
spammysammich Lieutenant Colonel 3073 Rep 1,799 Posts Drives: 2009 E92 M3 Dakar Yellow II Join Date: Oct 2021 Location: Edmonds, WA iTrader: (0) Garage List 2009 BMW M3 [10.00]	At that mileage you cannot rule out stuck or gummed up fuel injectors. They’re a known weak spot in S65/S85 motors.
	Appreciate 1 ZachE90M3148.00 Quote