E53 3.0 no power/sputtering (further diagnosis)

[itsbrokeagain]

So I picked up a 2006 3.0 two months ago and spent that time doing much needed repairs to it. Previous owner had performance issues and after the dealer raped them for nearly 12k in repairs a year ago and were asking another 5k more this time, she put the car up forsale.

Being a BMW mechanic for the better part of 10 years, I went in and did the basics:

-New fuel filter (old one was black)
-Air Filter
- 6 new plugs and a coil pack
-Lower intake boot replaced
-CCV system was done by the dealer a few years back
-Water pump/t-stat/radiator/hoses

Truck ran great. Due to the mileage (116k) I was getting ready to do the fuel pump as well since the one in my girls 2003 325xi crapped out 3 weeks ago at relatively same mileage. I used to change them all the time in 2007-8 when they had a rash of them failing due to all the ethanol.

Over the last few days I've noticed that it would long crank, sputter for a half second and then run fine on cold start. Warm start no issues. Drives perfectly fine. Priming the fuel system twice (turning the key on twice before starting) alleviated that issue, which made me think the pump is getting weak and not priming adequately. Also made me question the brand new fuel filter I put in since such issues are usually the result of a bad fuel pressure regulator (Mann Brand)

No codes up until this morning. Went to cold start the truck, long cranked and stumbled, except wouldn't really hold an idle. A few more tries and it runs, but I can feel a miss and hitting the gas results in a stall.

Fired up PASoft, got P0172 and 175 codes (banks too rich), as well as MaF shorted to negative. Cool no biggie, unplug and see if it will run better right?

Did so and still no change. But I do notice after 10 starts it will idle a bit better, but still down on power and doesn't want to accelerate. No misfire codes or anything aside from disconnected maf code.

Hooked up my snap on fuel pressure gauge which ironically find out doesnt work anymore, as it reads zero and the car is still running hahah.

Am I battling two issues at once here? Bad maf and a slowly dying fuel pump? I've dug up so many dead end threads where the issue never gets solved, and I read that changing the maf doesn't always solve the problem.

My friend has a Maf on order for me tomorrow, worse case I send it back if it doesn't work...

*edit* I also just filled up yesterday afternoon with 92 from a new station by my shop that is only 4 months old at the most. It had previously 3/4 tank from whenever it was last filled 3-4 months ago before being parked and I ran that tank down to 20miles DTE before filling up. Put about 60-80 miles on it since (Got it inspected/ran errands/dinner for valentines day) and not one quirk.

[itsbrokeagain]

Well fixed my gauge this evening (worn out o-ring) and checked it on a other car to confirm operation.

Swapped a new maf in for starters and no change. Hooked up the gauge and right off the bat, the truck only gave me 20psi on first prime. Second prime went to 45. As soon as I cranked it over, fuel pressure dropped to about 10-12 and truck would barely run. So it seems the result is a dying fuel pump. Just have to wait for the weather to warm up a little and change it out, and then off to the shop to change the fuel filter again incase the old pump decided to crap it's guts into it.

[victell]

Have you fueled up any of your other vehicles at that gas station? Might be a bad batch of gas. If you havent fueled up with any other vehicles I would make a call to the gas station to see if anyone else has reported problems to them lately.

[itsbrokeagain]

Originally Posted by victell

Have you fueled up any of your other vehicles at that gas station? Might be a bad batch of gas. If you havent fueled up with any other vehicles I would make a call to the gas station to see if anyone else has reported problems to them lately.

My E39 touring and my girls e46 also drink from there, I actually filled the E39 Sunday night with 92 octane from the same pump. Still running. When I pull the cover I'll have a look down in the tank to see.

[itsbrokeagain]

Since the weather today was decent and not really windy (45 degrees) I decided to tackle the fuel pump. Simple install and was done within 35 minutes. One prime and the truck fired right up. Roadtest to the local Starbucks and the truck feels a lot peppier.

Oddly enough the tank was spotless inside. Not a speck of dirt to be seen. Fuel pump was original with the wax seal giving it away.

[williamx5]

Originally Posted by itsbrokeagain

Since the weather today was decent and not really windy (45 degrees) I decided to tackle the fuel pump. Simple install and was done within 35 minutes. One prime and the truck fired right up. Roadtest to the local Starbucks and the truck feels a lot peppier.

Oddly enough the tank was spotless inside. Not a speck of dirt to be seen. Fuel pump was original with the wax seal giving it away.

Good day!!

Glad to hear it worked... It is odd the pump gave out so soon... OR maybe I was just super lucky with my 98 E39 540i... It had 217K miles when it died... It didn't do what yours did though... Mine DIED going down the highway at 75 MPH... Trailered home, swapped out the original pump, and life was good again... Mine had the original tape with the paint pen they use to quality check everything...

Oh, I did manage to put the siphon tube from the other side of the tank in wrong... So, once the fuel pump side of the tank went dry, I was out of gas... Luckily, I put two and two together... Little over half a tank on the gauge, but acting like I'm out... I did a hard swerve side to side to slosh some fuel to the pump side... That let me get to the station and fill up... Reseated the tube the next day...

Cheers!!!

[itsbrokeagain]

Originally Posted by williamx5

Good day!!

Glad to hear it worked... It is odd the pump gave out so soon... OR maybe I was just super lucky with my 98 E39 540i... It had 217K miles when it died... It didn't do what yours did though... Mine DIED going down the highway at 75 MPH... Trailered home, swapped out the original pump, and life was good again... Mine had the original tape with the paint pen they use to quality check everything...

Oh, I did manage to put the siphon tube from the other side of the tank in wrong... So, once the fuel pump side of the tank went dry, I was out of gas... Luckily, I put two and two together... Little over half a tank on the gauge, but acting like I'm out... I did a hard swerve side to side to slosh some fuel to the pump side... That let me get to the station and fill up... Reseated the tube the next day...

Cheers!!!

Yeah I didn't touch the siphon/suction jet side. That was working fine so I intend to leave it until it fails.

I believe the previous owner had been putting poor quality gas in it, judging by how black the filter was when I changed it.

My girlfriends E46 had 115k on it when her pump died, but thankfully it was at work in the parking lot, so a short tow later down to my shop I had it running again. Here's to another 150k!

[jsoto]

1/2 hr for a swap.

Takes me a couple minutes just to get all the fixins out to get to the negative terminal on the batt ;-)

I've done the hammer/screw locking tap eons ago.....on the E53, I got the socket for it.