Q: Bad fuel pump? 2004 BMW X3

asked by on February 20, 2017

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.

Car is hard to start Inspection $79.99 - $89.99 Get a Quote

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.

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