Q: Bad fuel pump? 2004 BMW X3

asked by on

Is it possible that a bad fuel pump can give a faulty cam sensor code?

The car had a "service engine soon" light on and was having issues starting and then one day it suddenly stalled. I took it into a shop and the fault code came back as the cam sensor. The sensors were replaced and the car is still really slow with starting. It seems to me like this would be the fuel pump as if I turn the key to the 1st position for a few seconds and then finally turn it over it will start on the first try after a couple seconds. If I do not do this then it usually doesn't start on the first try. I have to crank it a second time for it to start.

Battery and alternator were both checked and found to be fine.

My car has 139000 miles.
My car has an automatic transmission.

Hi - short answer is "No: a fuel pump problem will not cause a camshaft position sensor problem". But, we all know Murphy’s 2nd or 3rd law says that 2 things can fail close enough together to make us believe they are related. Check for problem codes, whether the Check Engine light is on or not. There will be very different codes for a cam position sensor failure, and a fuel supply issue (low fuel pressure at startup for example). I suspect you have either a leaking check valve in the fuel pump, or a fuel pressure regulator problem - either of which can make for slow starts due to low fuel pressure on startup. I recommend a hard starting inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, and give you an accurate assessment of damage and cost estimate for repairs.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Bad fuel pump? 2004 BMW X3

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Hard Starting 04 BMW X3

Hello there, many common faults will cause your 2004 BMW X3 to have a hard time starting. You have done great in diagnosis and replacing parts that will typically cause this condition. Common causes of a hard start are the...

Q: Getting error code p0340 on my 2002 Ford Taurus DOHC 3.0

Hi - yes, you are correct. This error code (P0340) means either the sensor, or the wiring and connectors for this sensor, are malfunctioning. Check the wiring connection for the sensor first, but most likely, the sensor has failed. I...

Q: Concern wether my 2 front axles really needs replacement?

Generally, the leaking from the axle shaft area is caused when the boots crack and the fluid is leaked out. The tricky part about identifying this is knowing when the boots actually cracked, when they began leaking and to what...

Related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.