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

[andrewwynn]

The needle shouldn't wiggle. That was the first signal wife's FPR was shot. Second was the rate the pressure dropped when the engine wasn't running.

It dropped 10-15 psi in an hour that's too fast and was zero overnight.

Did you do an extended power off test?

There is a tiny o-ring between FPR and fuel filter that fails and will cause pressure problems. But if the filter is 150,000 miles old even though they can last half a million they aren't that expensive I bought a new one and it solved the problem.

[workingonit]

Originally Posted by andrewwynn

1) The needle shouldn't wiggle. That was the first signal wife's FPR was shot.

2) Second was the rate the pressure dropped when the engine wasn't running.
It dropped 10-15 psi in an hour that's too fast and was zero overnight.

3) Did you do an extended power off test?
There is a tiny o-ring between FPR and fuel filter that fails and will cause pressure problems. But if the filter is 150,000 miles old even though they can last half a million they aren't that expensive I bought a new one and it solved the problem.

1) The needle barely quivered, but not as much as many I've seen before, on other cars, using a friend's Snap-On tester (which I wish I could get). Actually, all cars I've seen tested had a slight needle vibration.

2) On the first test, the needle stayed at 42psi for 10 minutes prior to me coming inside to post my results, and was still there about 30 minutes later after returning outside (possibly 50 minutes, total).

On the next test cycle, when I got the strange low pressure results, I presume that the dissolved O-ring had kept true pressures from being measured, and also was leaking pressure at the Schrader, so leak-down rate wasn't true either.

On the third test, after trying the fouled hose w/o the O-ring, it couldn't hold pressure much at all.

On the final test, using another/original fitting and lots of tape, I saw 49psi with the engine running, 42 just on prime, but it leaked quickly at the Schrader, but it confirmed the first test results:

• 49 psi running,
• 42 on priming,
• zero leakdown (while the test hose fitting still had a good O-ring), and
• overall, the FPR probably could be failing

3) Any extended power-off test (beyond the successful 50 minute test already done) will have to wait until I repair the new hose/adapter that failed me (via a new O-ring, and removing pieces of it that are clogging the hose).

Meanwhile, I'm texting the PO again, to try and get more specific answers concerning the FPR he presumedly replaced, and/or lifting the X5, removing the shield underneath, and looking for myself. But that'll have to wait, as the wife's out-of-town, and I may need her help to crawl out from under there. I told you guys I was old and broken, didn't I?

[workingonit]

Originally Posted by workingonit

Meanwhile, I'm texting the PO again, to try and get more specific answers concerning the FPR he presumedly replaced, and/or lifting the X5, removing the shield underneath, and looking for myself....

I got the (partial) info I asked for...he just replaced the regulator, ONLY, with a Bosch 0280160597 (BMW #13531436110). Why the filter wasn't done at the same time, I don't know, yet. I would've done both.

Another response, he thinks the filter is the original from 2001; the first owner was a cheapskate (and used it to go to drilling sites, so he just barely maintained it), and only replaced the minimum required, according to my friend, who talked with him a lot after their transaction.

My friend, who bought it to swap to me, just tried to get it running OK, at first, then redid the only bad items: cooling & suspension, and then only did the Vanos and timing chain/guides at my persistent requests, just before our car swap. The non-Android, non-BMW radio swap he did was to put a cheap radio in, to replace the broken/missing equipment, sorta as an afterthought.

I think I'll get a complete Mahle unit, when I can.

[workingonit]

Since my fuel pressure test fitting O-ring broke apart, I only have the inconclusive test results to go by: running pressure at 49psi (should be 51psi +/- 2.9psi, or so I read) so mine is within those limits). I saw 42psi priming pressure, which held for quite awhile before the O-ring came apart, which might be a bit low, but I've never had any trouble starting instantly, with no hesitation even at WOT. I'm moving the fuel filter & regulator to the back of my list, for awhile.

My extensive vacuum leak search (multiple times visually, with smoke and carb cleaner, too) came to naught, but I'm going to take apart all the post-MAF hoses & ducting to test off the car, using a vacuum pump and a magnifying glass, up close. I will also remove (and clean it out, this time) the ICV, which I just rattled last time. I never examined the ICV-to-manifold boot, so it comes off also. I'll also use the vacuum pump to test the line going to the FPR, prior to removal, while the engine is running.

I'm considering getting a cheap MAF first, for testing purposes & possible replacement of my Siemens MAF, which I and others think may be under-reporting airflow to the DME. Xchemist says he bought a $20 MAF that solved his problem, and is still using it. Perhaps he'll tell me where I could get one from the same source he did, so it won't be a crapshoot getting a decent one (for cheap), to compare to my "already cleaned" OEM MAF.

P.S. almost as an afterthought: I never actually removed the cowl, to go "hands & eyes-on" with the vacuum lines & fittings back there. I trusted the smoke to be visible, and/or the copious amounts of carb cleaner I sprayed behind the engine (using a long, flexible tube) to reveal any leaks back there. I was hesitant to remove the cowl, since it opens-up the innards of the HVAC to insects & other critters that may seek entrance if I can't reseal it immediately. I've had problems with insects (including scorpions), rodents (field mice, rats, & squirrels), and feral cats (especially kittens) trying to make my vehicles their home, so it's a real concern in my semi-rural wooded area. Did I mention snakes, too?

[X5chemist]

Originally Posted by workingonit

I'm considering getting a cheap MAF first, for testing purposes & possible replacement of my Siemens MAF, which I and others think may be under-reporting airflow to the DME. Xchemist says he bought a $20 MAF that solved his problem, and is still using it. Perhaps he'll tell me where I could get one from the same source he did, so it won't be a crapshoot getting a decent one (for cheap), to compare to my "already cleaned" OEM MAF.

My X5 didn't have the SES light on. I wanted a spare since it's a known problem. If it fails, I have the OEM one with 143k miles ready to install. I keep it in a zip lock bag. In 8000+ miles, the SES has not turned on once for errors.

Replacement MAF sensor. Due to inflation, it's $22!

[workingonit]

Originally Posted by X5chemist

My X5 didn't have the SES light on. I wanted a spare since it's a known problem. If it fails, I have the OEM one with 143k miles ready to install. I keep it in a zip lock bag. In 8000+ miles, the SES has not turned on once for errors.

Replacement MAF sensor. Due to inflation, it's $22!

I replied on the other thread, after you posted the link, https://xoutpost.com/1220634-post15083.html.

Out of stock, and not even listed on the "mostplus" parts website, but I found it on Amazon for $23.58, and ordered it immediately. Even if it doesn't solve my lean code problem, it can serve as a so-far-reliable (as it has been for you) back-up for mine. At least it'll eliminate the MAF as the problem, I hope.