stall on ZX - "beat motor"?

Hi gents,
my 1992 1.6 ZX has an occasional stall. my mechanic says it's to do with what is called here by translation "beat/pulse motor". AFAIK, this is the element inside the fuel injection that distributes
the mixture while idling. the stall can appear either when begininnig to accelerate from idle, but also in sudden acceleration from about 1,500 rpm (for example coming out of a slow turn etc.). since this part is rather expensive, the good man cleans it on occasion, but tells me I might have to get the new one eventually.
my question: is the non-idle stall also directly related to this beat motor? (...if this beat-motor only does the idling, why does it have an effect in higher rpm's?)
(* the following are good: fuel pump, fuel filter, ignition cables).
Thanks in advance, Ido

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