97 Echelon engine surging-TPS?

[Jcowan]

My 97 malibu echelon lx with black scorpion efi is surging at all rpms. You bring it up to speed and sometimes it feels like it's underpowered then a few seconds later it will take off to more where it feels like it should be (both in terms of rpm and speed) then it will slow back down and keep going back and forth. The intervals are not regular and it may go up by 100 rpm one time then 300 the next then 50, etc. No rhyme or reason. Does this sound like a tps?
Doesn't seem like it's a transmission slipping or lack of fuel as it doesn't sputter or hesitate. When it decides to increase, it goes, no hesitation. 
Does this with PP on and off. 

Any help much appreciated. New to us boat and I want to ski!

[Jcowan]

 

 

[NHolladay]

Have you xhanged your fuel filter.  Had a similar issue.  Spent a ton of $$ chasing it.  Even though I thougjt no that was it and it was a $10 5 minute job

[DOJOLOACH2]

Did you get this resolved OP? 

[JasonK]

Search this site and you should be able to find a few suggestions. I remember one problem with an echelon that took a long time to find. Something about a canister assembly.

[Michigan boarder]

53 minutes ago, JasonK said:

Search this site and you should be able to find a few suggestions. I remember one problem with an echelon that took a long time to find. Something about a canister assembly.

That was with a 454, different engine.