1999 528it progressively rough idle p0130 p0150 p1250

[jfwainscott]

Hello!

I've yet again hit a road block with o2 errors. Vehicle was sitting for around a year while I was away, but i got my friend to start it up and drive it around the block every week or so. I got these codes ( p0130 p0150 p1250 ) and began the usual steps of checking all the vacuum lines but to no avail, so without a smoke kit I decided to just replace the whole ccv with a catch can and not have to deal with tracking down a air leak. After installing my catch can (with no breather) the issue persisted so I continued with my preventative and other maintenance hoping that I could some how tangentially fix the issue. Replaced the fuel filter, fuel pressure regulator, both intake boots , camshaft position sensor A, the airbox and filter, replaced the pin and flap in the disa valve, the starter, and manifold gasket, but still no luck on the issue. Its a rough idle on start that gets progressively worse and shaker the more it sits at idle doesn't matter if its warm or cold. I also don't quite know what code p1250 is, my reader says manifold pressure too high, but the forum said fuel pressure issue, so maybe its the fuel pump or maybe a bad line going to the fuel pressure regulator, but I really don't know. Asny help would be great.

Thanks!

[ross1]

Modifying the CCV system while trying to diagnose is a shot to your foot.
Having said that with those codes I'd be looking at live data from the O2 sensors, checking for vacuum leaks and fuel pressure.
aside rough idle any other driveablity issues? Okay at full throttle?

[jfwainscott]

I don't think so? It seems slow in the lower range more than anything, and hitting the throttle from a full stop takes a second for it to do anything sometimes.

[BMW4RE]

I may be mistaken, but I believe that a bad Vanos might give you bad throttle response in the lower range. I'm taking it for granted that you have replaced all of the Vanos seals, etc., at some point? Yes?

A few years back I had what felt like a rough idle. What it ended up being was one of the motor-mount arms was completely broken. And if you have such an issue on the passenger side, it might imperil wires from the 02 sensors, thereby triggering a code or two. Just throwing it out there.
Good luck.