Engine still surging on acceleration

[1995 525i]

I'm hoping you guys can help me. My car still surges when I accelerate hard. I can see the tach climbing then pause and climb some more. Once it gets going it pulls very strong but it doesn't pull straight through without the surging hesitation. I've changed the spark plugs. What else can I do?
Oxygen sensor? Fuel filter? What would make it do this? Also, when I accelerate off the line, the engine doesn't grab immediatetly. There is a slight hesitation. I have to mash the accelarator twice. I've added some redline fule injector cleaner but haven't noticed much difference.

Any ideas?

Thanks!

[bpattan]

i had this problem with my '95 530 some time ago. my intake manifold boot was cracked and letting in a large amount of unfiltered air. check to see that the boot is cracked. you'l have to squeeze the boot since it's not obvious when looking at it. often the boots crack after a while, when the engine revs it stresses/kinda twists the boot. good luck. bob in houston.

[Karl]

...or some vacuum leak. If you don't see a crack in the intake boot (between the throttle and air sensor), check all your vacuum lines.

[1995 525i]

Thanks guys...I'll check into it.

[dreamer_bimmer]

Hi there,
I just had a similar problem. The car started fine and pulled away but as i went along the road the engine was struggling to go above 2,000rpm. I had to pull over. the engine never cut out but it took a while before it was acting normally. Could this be the same problem? It was sitting out in the rain for about an hour before I pulled away.
Thanks