Black scorpion efi throttle position sensor?

[Justin_C]

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!

[Justin_C]

[ToddF]

When my tps has gone bad it will hold idle at different rpms as high as 300 higher than idle

One thing for sure is it will get worse if it is a tps. They have aplastic housing that wears out or seats the tb blade in the wrong spot

[Justin_C]

@ToddF mine will idle at higher rpms sometimes (up around 11-1200). When I shut the boat off and turn it off it will go back to a lower rpm. (usually somewhere between 600 and 800). So I guess what you say is true in my case. No consistent idle

[ToddF]

Sounds like mine, takes only a minute to take it off and look at the housing to see if it is marred up

The hard part is getting it back on that takes some finagling

Even if it looks decent it can still cause the sticking idle