reset fuel trims; lasted about 60 miles or about an hour

[workingonit]

My friend replied to my query, and said he had replaced the filter, but doesn't remember if it had the regulator attcahed. I'm assuming that he bought it as a unit, of which the most common I see sold online is the combination of both, together.

I still plan to get a fuel pressure tester, since even a fairly new regulator can fail (I've had three fail on my old Chevelle racecar), so maybe the problem stayed with me, on another car. My garage is haunted.

[andrewwynn]

Within the past year somebody posted about FPR that failed within months or was even DOA.


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[workingonit]

I found a (partial) Foxwell .pdf that lists what functions their scan tools can perform on BMW's. Among those listed, in the Sevice Functions pages, it shows that I should be able to monitor the fuel pressure on my scan tool. I haven't located it, yet, but it sure would answer the question if I have low fuel pressure causing my recurrent codes.
zoom it to 150% for reading

I've pretty much completely tried most functions that I dare, but haven't found that one. Meanwhile, using the same NT510 Elite tool on my '04 Chevy 2500HD pickup (as an after "long trip" checkup), I was made aware of how many more functions I could do on the GM product that I couldn't do (or maybe couldn't find...) in the BMW programming. More complete graphs for example. Long item checklists for those graphs, etc.

Maybe the NT510 Elite doesn't have that function available, despite the list? Still waiting to buy the OTC 5630 fuel pressure test kit, if I can't find a way thu my scanners or apps.

I reset all adaptations yesterday, and drove about 3 miles without the fuel trims going critical, staying at 10.16 long term on both banks, and about -3 to +3% short term on both. I just can't depend on resets all the time, because the problem is still there, just hidden.

[RocketyMan]

Originally Posted by workingonit

I went outside to prepare my camper for my trip, and since I had to move the X5 aside to pull the trailer out of the garage, I grabbed these photos of my Torque Pro-dedicated phone in the X5.
Attachment 82040 the usual suspects

Attachment 82041 MAF graph at 1k, 1.5k, 2k rpms

I had trouble keeping the speed exactly on the marks of 1k, 1.5k, and 2k rpms, but it is close enough. 1k yields roughly 6 g/s, 1.5k yields about 8 g/s, and 2k rpm yields slightly over 10 grams per second.

Since a rule of thumb on a MAF's air flow rate at 500 rpm is 1 gram per second per liter of engine displacement (or 3g/s for my 3.0l), my graph is just about right at 6g/s at 1k rpms, a bit low at 1.5k rpms, and really low at 2k rpms (it should be 3x4=12 g/s). Am I reading this correctly? I did read the MAF momentarily, while driving at 70mph yesterday, it read 20+ g/s. I forgot the rpm, though.

Just now getting back to your message.

So you're correct in your assertion. So the faster it was idling (with no substantial engine load) the more air you should be getting at an interpolated rate that corresponds to your engine displacement.

For your vehicle, this seems to make sense and coincide with the two fault codes of "lean" since your MAF is reading low in this case. I would suggest searching for a common vacuum leak of some sort. Sometimes you can tap on the MAF and if the reading jumps--it's a bad MAF.

But besides that, what have you done since? Did you inspect for any leaks? The intake boot? How about DISA gasket?

[Effduration]

Originally Posted by workingonit

I found a (partial) Foxwell .pdf that lists what functions their scan tools can perform on BMW's. Among those listed, in the Sevice Functions pages, it shows that I should be able to monitor the fuel pressure on my scan tool. I haven't located it, yet, but it sure would answer the question if I have low fuel pressure causing my recurrent codes.

I am not aware of a fuel pressure sensor on an M54 equipped car. If there is no sensor, there is no way the Foxwell can read it.

you may be able to borrow a fuel pressure tester form the auto parts stores, or find one used on FB, or buy it at Harbor Freight.

[andrewwynn]

+1. I can monitor pressure on my e70 not on my old e53

[workingonit]

Originally Posted by RocketyMan

... your MAF is reading low in this case. I would suggest searching for a common vacuum leak of some sort. Sometimes you can tap on the MAF and if the reading jumps--it's a bad MAF.

But besides that, what have you done since? Did you inspect for any leaks? The intake boot? How about DISA gasket?

Actually,

• 1) I did the smoke test 3x before it broke,
• 2) then a complete MAF cleaning (with MAF cleaner, of course...also verifying that it is a genuine Siemens/VDO 5WK96132Z),
• 3) then the carb cleaner spray-down (of all vacuum lines, intake boots, injectors & o-rings, etc., including the totally rebuilt DISA that I used the GAS kit on...with new gasket, too, recently), and
• 4) also spraying the SAP & even the brake booster hoses (inadvertently spraying the aux water pump wiring, which triggered a weird code),
• 5) replaced the seeping oil cap and gasket (there was an oily streak going straight back on top of the beauty cover), and
• 6) repeatedly disconnecting and reconnecting the MAF while running, which reset my fuel trims (for awhile, at least).

All those actions occurred two weeks before I started this thread. Then there were doctor appointments, then the mysterious flat tires, then the camping trip, followed by resting for a few days. I'm ready for the next round of futility!

I agree that my MAF readings are a bit low, but I'll try tapping/wiggling the sensor and the plug, to see if it affects the idle.

And, Effduration and andrewwynn, I think both of you are correct, and I'll have to do a manual test on the fuel rail. But, will the tester kit at Harbor Freight have the correct Schrader valve adapter?
The only test kit I've read about on this forum that had the correct fitting was the OTC 5630.

[andrewwynn]

Mine is the $25-30 HF kit. Worked fine (the second time ; the first one leaked at the gauge).


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[Effduration]

Originally Posted by andrewwynn

Mine is the $25-30 HF kit. Worked fine (the second time ; the first one leaked at the gauge).

I have Pittsburgh model 62623 ...Harbor Freight $ 14.97 (Jesus that's cheap)
I wrap a layer of teflon tape around the schrader valve threads and at all connections, and I am good to go. I have used it on all my BMW's for 3 years without problem.

https://www.harborfreight.com/fuel-i...ter-62623.html

[ahlem]

I just went through this on our 325i 2002 and my home made smoke tester defined the problem perfectly in 3 locations. The first location was a split in the intake boot on the underside where a second hose tees off to the Idle Air Control valve. After I changed the boot it was a fuzz better but not a lot. I tested it again and the hose coming off the brake booster goes into a plastic valve that had come unglued at the mid line. JB Weld and super glue solved that problem. The final smoke test (so far) showed the DISA valve leaking where it goes into the intake. Some silicone gasket maker to fill in a bad spot in the molded silicone sealing areas seems to have done the job. It's 95% better so I will wait for a bit and re-test with the smoke tester. My situation is a slightly rough idle. I also cleaned the Idle Control Valve just because I was in there. This is almost identical to the 2001 3.0 X5 when I put it back together after a head gasket job about a year ago. Both have 180k miles.