LQ9 stumbles on start

[skisix@38]

The boat is a 04 TT197 with LQ9 and slot and we've tried several props now with the same result. The issue is that after warming up the boat hesitates or stumbles when the throttle is pushed forward to pull up a skier and then it catches and run fine pulling the skier up and performing like it should.

Does anyone else have this problem? Heard of it? have any idea what to do?

To me it seems like when the throttle is initially pushed forward air rushes into the manifold very quickly and almost stalls it until the computer senses it and retards the timing or something and then it runs. Otherwise the motor is very strong and it gives a good pull.

And for those that think I'm just trolling for trouble - go away. This is a new lake members boat and he is asking for help. Not to mention that his boat has a heater in it and mine doesn't.

JimN?

[east tx skier]

Was the LQ9 the one that had the hood scoop on the motorbox?

[skisix@38]

Originally Posted by east tx skier

Was the LQ9 the one that had the hood scoop on the motorbox?

No, this is "83 of 100" standard TT boats only it has the 6L northstar engine, 383HP. He says that it only recently has exhibited this issue but, that may because he hasn't really put many hrs on it since he bought it last year.

[lakes Rick]

I would check your fuel pressure and be prepared to install a new fuel pump......

[gregg]

Could be MAP sensor or MAF (not sure if they use any speed density fuel control systems yet) or perhaps a TPS as it simulates what the accelerator pumps did back in the carb. days by adding extra fuel during quick throttle openings.

[skisix@38]

Originally Posted by lakes Rick

I would check your fuel pressure and be prepared to install a new fuel pump......

What should I expect to see? 50PSI? and what is the tolerance? Should I expect it to drop some on pulling a skier up?

[Ric]

Originally Posted by skisix@38

The boat is a 04 TT197 with LQ9 and slot and we've tried several props now with the same result. The issue is that after warming up the boat hesitates or stumbles when the throttle is pushed forward to pull up a skier and then it catches and run fine pulling the skier up and performing like it should.

Does anyone else have this problem? Heard of it? have any idea what to do?

To me it seems like when the throttle is initially pushed forward air rushes into the manifold very quickly and almost stalls it until the computer senses it and retards the timing or something and then it runs. Otherwise the motor is very strong and it gives a good pull.

And for those that think I'm just trolling for trouble - go away. This is a new lake members boat and he is asking for help. Not to mention that his boat has a heater in it and mine doesn't.

JimN?

is this Rodltg's boat
sure sounds like it could be???????????

[gregg]

If it skies ok and runs ok at higher rpms or wot, it seems unlikely it would be a pump problem, but a pressure\volumn test would def. be in order to rule it out.

[ski_king]

Originally Posted by Ric

is this Rodltg's boat
sure sounds like it could be???????????

Unlikley, his is listed on Ebay now. Rod, you better hope for some last minute bidding.

[rodltg2]

very funny, mine is still sitting in my backyard.