Renault Megane eratic high revs. Help?

[Potsy]

Our 1997 2.0 Megane has a problem. When you put your foot down it gets to 3000 revs and jumps rapidly between 3000 and 2500 revs. It won't go any faster. The rev counter needle flickers like a broken speedo does (if you know what I mean?) It calms down when you ease off the throttle. Also does it in neutral. Drives great apart from that. Can anyone help, please?
Regards
Potsy

 

[davydunt]

sounds like the ecu has developed a flat spot around that point (common in high performance ecu's)

a word of warning... if you change the ecu and its still there don't shoot me