Bad Bad X5
 

01 E53 3.0 I am having problems with my X5. When its below 70 degrees it wont start. It will crank fine but never even pops. Once its warm it fires right up every time. then next day nothing.

I have recently replaced:
Camshaft sensor
Crankshaft sensor
Fuel pump

My thinking is a relay. I dont know which is the fuel pump relay. The one in the cargo area or the one on pass side firewall by the DME. But I have swapped them around.

I used a meter and wasnt getting power to the pump. Now that it has warmed up I do for about 3-5 seconds. Normal I believe. This is to prime the fuel line. The weird thing is that when I hook up the fuel pump I get no gas out of it during those 3-5 seconds? It never kicks on. There is no pressure at fuel rail. No gas at all.

Sounds like a dead fuel pump.

Change the fuel pump. The temperature inside the fuel tank is lower than the outside ambient temperature. It is possible the fuel pump is literally frozen when you first try to start it. If the car senses a problem with the fuel supply, it will shut off power to the fuel pump to prevent damage to the cats (prevent excess fuel). Since you already have it all opened up, replace that pump.

was you fuel pump left? chinese?

I changed fuel pump assembly from BMW parts here in Tucson today. Passenger side. I dont get power to the pump! Only for 3-5 seconds then it shuts off power. I am checking at the plug on top of the pump. When i plug it back in the pump doesent hum or anything.

Dead pump. You only get power for a few seconds (priming) before the engine is running.

Its a brand new OEM pump and assembly from the dealership. How can it be bad? Ive heard of it before but why when I put a hose on the pump into a bucket I get nothin? I would think it would prime until pressure is reached. I know before startup the only run for a couple secons but I get nothin.

Try connecting the fuel pump to a 12v direct source like from the battery with leads or a battery charger. Check that the pump itself is working - at least to eliminate that issue.

Could be a bad transfer pump. it will show a tank with gas, but the fuel pump side of the tank is empty. The float level of the gauge is on the driver side (LHD) of the tank and the fuel pump is on the passenger side of the tank.

When I changed the pump it was 3?4 full . The problem lies between the DME, relay or a bad brand new OEM pump. I need to jump it this morning to see if its a bad pump,

Are you or are you not getting power at the plug for the fuel pump? If you are for a couple seconds when the key is first turned on then shuts off, this is normal operation and your problem lies within the pump assembly. If you aren't getting Any power to the plug, check the fuel pump relay (located above the fuse panel assembly behind the glovebox --you need to drop the fuse panel to get at it).

Edit: did you change the entire fuel supply assembly, or replace just the pump? If you swapped just the pumps, be sure to double check your connections on the pump itself!

I get 2-3 seconds of power only after it warms up. The outside temp to 70. Are you sure the relay is behind the fuses in the glove box and not in the compartment in the engine bay? I hear a clicking there then the power to the pump stops. But this is only one problem. Other problem is the pump never started for 3-5 secons after I verified power.

Pull glove box, drop fuse panel and it's the green one top left.

Pulled the glove box no green relay. Will pull fuse box now but not sure why it would be behind it.

Found it. Replacing now. It was a new complete assembly

Swapped out and not getting power to the fuel pump plug. Where do I go from here? Is there another Relay? Something electrical warms up and makes contact. Then I will have power. What is before This relay?

If you're getting power to the fuel pump plug the relay is working...

I don't have the diagrams handy...but IIRC the fuel pump relay functions on a grounding circuit with the DME. Basically what happens is when you turn the key, the DME grounds the relay trigger -- completing the circuit, closing the relay and thus sending power to the pump. I don't know which (if any), other conditions need to be present/have an effect on whether or not the fuel pump is powered though.

Just so were on the same page:

With the original fuel pump relay in place, when you turn the key, you don't get power to the vehicle side of the fuel pump plug unless its above 70* or Do you get power for a couple seconds to the pump plug independent of temperature, and it just doesn't start below 70*?

Have you fired up the pump to make sure that it does in-fact function?

Jumped the new pump and it works. I do not get power to the pump plug until it is warmer. It's 83 now and still no power.
Maybe somebody set a alarm. It only starts in the afternoon.