95 540/6 running bad again

Car is running really bad again. After i changed the fuel filter the car ran normal for a couple of days, then started doing it's thing again. CEL comes on when just cruizing down the road and at idle. If u give it a little power it will clear up and run great. Sometimes it feels like it has no power on acceleration, but most of the time it will clear up. At idle it sounds like a 4 cylinder. Also at slow speeds when u let off the gas the power steering feels like it is binding, like the engine is not turning fast enough. Then all of a sudden it will run great for a day, but go back to running bad. Also my mpg is down by at least 2. Went and changed the fuel filter again, but no help. It seems to be fuel related. I changed MAF with my 540/a, no difference. Anyone have a idea?

Have you checked the fuel pressure? A failing pump could be the issue.

540? why does your name and sig indicate a 525?

Because i used to have one and have not changed it.

I did change it out with the one from my other 540 because it seems like fuel pressure but there was no change.

You say your CEL lights up. Can you read the codes that it stores? That will generally help with diagnosis. I remember when my 535 had low fuel pressure, it would throw an O2 sensor code because of a lean mixture under throttle. You 540 should be able to output the code for you.

No, i have tried many times to pick up the codes. Ive heard some cars for whatever reason the stomp test does not work.

Stomp test should work just fine. Seems that not everyone is successful in doing it though. Most people apparently don't do it fast enough.

Well i have tried many times as fast as possible. I dont know how i could do it any faster.

Your CEL isn't burnt out, right? And you're sure you've got the key turned over to the right position? I forget if you need position 1 or 2 as I've not bothered with it much as I've got a code reader.

Have you been able to get it to work on any other E34? It works fine on my M-Sport (9/95 build) as well as a friends '95 525iT (6/94 build).

Oh, and it doesn't work on Euro E34's as they don't have a CEL. But as far as I know if you've got a CEL it should work just fine.

Barry,

My brother's 525 had us thinking that it just wouldn't spit out codes for a while. Eventually my bro got the timing just right and it worked. Are you pressing the pedal far enough to hit the kick-down button?

Edit: Just saw that the car in question is a 6-speed. No kick down button there.

position 2 is correct.

Quote:

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Originally Posted by bubba966

Your CEL isn't burnt out, right? And you're sure you've got the key turned over to the right position? I forget if you need position 1 or 2 as I've not bothered with it much as I've got a code reader.

Have you been able to get it to work on any other E34? It works fine on my M-Sport (9/95 build) as well as a friends '95 525iT (6/94 build).

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I would think it is the crank position sensor.

Have the intake gaskets been replaced yet? My car gave all the same symptoms at about the same mileage and I was never able to track the leak down with the carb cleaner test (I suspect the PCV plate to have been the culprit), but doing an intake refresh made it run like new again.