Suzuki m18a rpm input erratic

[Jeff b]

Hi we are having trouble with an Atom g4 running a suzuki m18a turbo in jet boat.

Originally wired up and running fine for approx 20 hours. 

Now is missing badly above 2000rpm, tried the simple things first, plugs, leads, coils. No change.

Plugged in lap top and rpm signal seems to be going nuts and is hitting rev limiter (6900rpm) at about 2000engine rpm? 

We swapped out the crank angle sensor, no change. Will try cam sensor as easy check but I'm thinking it's not the issue?  

Does anyone have any idea what would cause the RPM input to skyrocket like this? 

 

[Adamw]

You can attach your tune and a log of it running as a starting point, but it sounds like a trigger problem so we are probably going to need a triggerscope from a higher-end ecu or a standalone oscilloscope to get to the bottom of it.  Do you know anyone with a Storm or higher ECU that you could plug-in to get a triggerscope?  Or do you have a scope?  Where abouts are you in the world?

[Karl Murton]

On 1/28/2020 at 7:37 PM, Adamw said:

You can attach your tune and a log of it running as a starting point, but it sounds like a trigger problem so we are probably going to need a triggerscope from a higher-end ecu or a standalone oscilloscope to get to the bottom of it.  Do you know anyone with a Storm or higher ECU that you could plug-in to get a triggerscope?  Or do you have a scope?  Where abouts are you in the world?

Adam, we are in the Hamilton/Rotorua area,   it's actually a Monsoon ECU,   attached is the tune and log files,  the crank sensor (hall effect) has been swapped to eliminate that as the issue. Will have a look on the trigger scope when we get a chance.  

James 27 jan 2020.llg Aniphenua Suzuki M18 turbo - James.pclr

[Adamw]

Yeah definately a trigger issue.  VVT doesnt look happy either.  Can you try turning Aux 2 off temporarily just to see if it is any happier with the cam not moving.