89 535i - Slow response and Lag in Acceleration

[LeaTHER OpT. 28]

There seems to be a lag in my car when i press the gas. It will not respond right away. It will drop to about 300 rpms then start accelerating. Then when it gets into the higher rpms (around 3000-6000) it starts to 'lag' by slowing down and speeding up in short bursts. Im not sure what the problem is, and am kind of upset with my cars poor performance. Anyone have ANY ideas as to what my problem could be??

[Aston_Jag_Tech]

I have somewhat of the same issue. I have a M30 with 250k. My cams are very worn, but my compression is acceptable. I worked a little bit on it and I am leading my tools to the Cams, Lifters, Rockers, and Idle Air Control Valve.
I would really like to check the TPS and Air sensor but I dont have a Oscilliscope..anyways....

I first checked compression, it was around the 135+, then I checked my valve Clearances, I set them a little tight since my cam is very worn but not too tight. I then looked at my chain tensioner guide and it was not there! I replaced the chain, guides, tensioner piston and shoe rail. Reason I went right away towards the chain tensioner is because there was so much slack in the chain and parts were missing. I had the same problem. Not as inclusive as before, a little lunging while WOT. I have not replaced my IACV. I deminished all my vacuum leaks which helped a little with the idle. But what really needs to be replaced are the cams etc. First start Mechanical and then the next step is electrical is what I believe.