2001 X5 4.4i issue NEED HELP
 

Hello everyone. This is my first post, and let me say ahead of time that I have searched both Xoutpost, and google, and have not come up with a definitive answer.

I sold my X5 to my mother. About a month later, this being last week, the car just dies in traffic. It restarted, and seemed to idle ok, but when pressing the gas pedal, it would studder and backfire, not moving forward at all. I had it towed to my house. I hooked my scanner up, and got the code P0102.

I tried the unplug the MAF while running trick, knowing that it may not be a real indicator, and it died. It runs the same with or without the MAF plugged in. I have checked the plug and the wiring, and it all appears to be good. I checked all of the hoses and lines, and can't find a vacuum leak. I then bought a new Bosch MAF, and hooked it up. Nothing has changed. I unhooked the neg. terminal on the battery, hoping to reset the computer. The only difference is the SES light is gone. It still runs as stated above.

Does anyone have any idea what could be causing this? I assume it is MAF related, but I am at a loss as to how.

Thanks!

Yeah, you could have a dying fuel pump. Connect a pressure gauge and see what type of pressure you have at the rails. A bad fuel pump will not throw up any code , except maybe a P0171 P0174 which are lean codes.

Do you know what the fuel pressure should be?

Key on engine not running it should be around 3.5 bars +/-.2 bars.
Engine running 2.5 - 3.2 bars

What scanner are you using?

The P0102 code does indicate a problem with the MAF. I would start by checking air intake such as a very bad air filter or a crack in the air intake tube after the MAF. I would check for broken or chaffed wires in the MAF connection or a bad ground. It is possible to purchase a bad MAF. I would clean the old one with MAF cleaner and see if that makes a difference.

FYI-The idle control valve can cause a misleading MAF code.

Not saying fuel pressure could not be the problem. Many auto parts stores rent what you need to check fuel pressure.

I have eliminated the MAF as the problem. I caused the P0102 myself, and in a moment of stupidity, didn't realize it. As suggested above I have moved on to a fuel pump test. I picked up a pressure test kit today, but I can't seem to find the shrader valve. It may be right in front of my face, but I want to be sure. Can anyone tell me where it is located?

http://i.ebayimg.com/00/s/OTYwWDEyOD...Uw-wP/$_57.JPG

It looks like a cap for bike tire or car tire, unscrew the cap and you'll see the valve. Cautions don't crank the gauge fitting down with tools, just use your hand. You don't want to snap off the shaft that the fitting attaches to.