Hesitation when accelerating

I have an '89 525i with the m20b25. My problem is that it hesitates when accelerating from a stop. I can recreate the problem while idling in park and blipping or opening and closing the throttle very quickly. The engine almost wants to die for a second but then it comes back and accelerates normally.
Could the temp sensor be causing this?I have also heard of the fuel pressure reg. causing this,is that true?
I have checked for vacuum leaks and replaced a number of hoses and gaskets already. I have also replaced the fuel filter,and replaced plugs,cap,and rotor and cleaned the ICV.

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This post was auto-generated based upon a question asked on our tech article page here: Pelican Technical Article: BMW E30 Coolant Temp Sensor Replacement

[Wayne 962]

I'm betting that you still have a vacuum leak in there. Check out my article on diagnosing them: http://www.pelicanparts.com/techarticles/Boxster_Tech/21-FUEL-Vacuum_Leaks/21-FUEL-Vacuum_Leaks.htm The throttle doesn't respond too well when there are leaks - I would check the idle control valve too, as well as the hoses that connect to it.

- Wayne