Surging Power Band

[Bullhead]

Hey all I am still working on my ntm (new to me) e30. It feels strong while driving but it surges at part and full throttle. It's not a whiplash surge it's like it goes in and out just a little but it is noticeable.
I would also like to add that it idles to low imo, my tach isn't functional or I would be more specific but I know it's idling so low it's almost at the point where it would die but it hasn't. I saw an adjustable idle screw on the TB but it looked to be sealed with lock tight.

[Andy.B]

I would check the fuel pressure and check thoroughly for vacuum leaks. After that, you might have a worn spot in the AFM armature track, which would cause inconsistent and inaccurate AFM readings.

[Bullhead]

I would check the fuel pressure and check thoroughly for vacuum leaks. After that, you might have a worn spot in the AFM armature track, which would cause inconsistent and inaccurate AFM readings.

Is the AFM an air fuel management computer? Sorry this is my 1st Bimmer. Where is this located and how do I fix it, I have done the spray test on all hoses with the engine running and idle stayed the same. I will do a home made smoke test this weekend.

[Andy.B]

AFM stands for air flow meter. It uses a spring loaded door with an electrical sensor that essentially gets blown open by the flow of air into the engine, and measures air flow by the door position.

The track that the sensor travels can become worn over time, leading to incorrect readings.

http://www.r3vlimited.com/board/showthread.php?t=247831

Before you go tearing into it, however, I would obtain a Bentley manual (if you don't have it already), a bolt meter, and a fuel pressure gauge, and work through the fuel injection system tests to locate any problems. The tests are simple and easy to follow, and will help you ensure everything is functioning properly.

[Bullhead]

AFM stands for air flow meter. It uses a spring loaded door with an electrical sensor that essentially gets blown open by the flow of air into the engine, and measures air flow by the door position.

The track that the sensor travels can become worn over time, leading to incorrect readings.

http://www.r3vlimited.com/board/showthread.php?t=247831

Before you go tearing into it, however, I would obtain a Bentley manual (if you don't have it already), a bolt meter, and a fuel pressure gauge, and work through the fuel injection system tests to locate any problems. The tests are simple and easy to follow, and will help you ensure everything is functioning properly.

Roger that, thanks again.

[Bullhead]

I was also wondering if it was a good idea to polish the door on the AFM. I now know how it operates so it seems like flow needs to be a smooth transition through here. This may be useless just asking so I will know next time, I have a bad habit of polishing everything lol.