Tacho oil gauge different to maliview oil gauge

[Matho818]

Hey crew,

have recently had some intermittent  starting issues with my 2013 Mxz which I am struggling to diagnose.

When the motors warm I’ll switch it off and occasionally when i go to restart it, the motor will just crank over but not fire up.

ive noticed when this problem occurs the oil pressure psi on the tacho stays at 0.0 psi.

 when the boat is running fine the gauge says 320 psi !!  The gauge on the maliview screen sits around 40-50psi.

any one know why the gauges are so different? And does it have to see oil pressure to start up?

motor is a 350ss monsoon

Appreciate any advice !

[formulaben]

I can't say for sure it applies to your motor, but for a lot of Indmar 350 motors the following info below applies.  Given that you have an oil pressure issue, I'd consider changing the oil pressure switch and/or sender that sends info to the ECM for your motor.

 

Initial Crank Action:

If you then rotate the key to the start position the engine will rotate.  Once the oil pressure has reached 4 PSI, the oil pressure switch will close allowing the fuel pump to run.  The crank position sensor will send a string of pulses to the ECM in response to the engine being rotated by the starter. These pulses continue as long as the engine turns (both starting and running) and if they are not present, the engine will not run.

ECM Reaction:

If the ECM sees oil pressure greater than 4 PSI and the reference pulses from the distributor, it will energize the injector drivers which will begin pulsing the injectors on for 4 ms (milliseconds) periods. The ECM will also pull in the fuel pump relay in effect paralleling it electrically with the oil pressure switch.  The ECM also monitors the TPS (Throttle Position Sensor mounted on the throttle body assembly) and wants to see .54 volts at this time. If it sees more than 0.54 volts, it will assume the engine is flooded.  Assuming the ignition module is good the engine will "catch".

[Matho818]

2 hours ago, formulaben said:

I can't say for sure it applies to your motor, but for a lot of Indmar 350 motors the following info below applies.  Given that you have an oil pressure issue, I'd consider changing the oil pressure switch and/or sender that sends info to the ECM for your motor.

 

Initial Crank Action:

If you then rotate the key to the start position the engine will rotate.  Once the oil pressure has reached 4 PSI, the oil pressure switch will close allowing the fuel pump to run.  The crank position sensor will send a string of pulses to the ECM in response to the engine being rotated by the starter. These pulses continue as long as the engine turns (both starting and running) and if they are not present, the engine will not run.

Cheers for the reply I will look into it, is the pressure switch located near oil filter?

[formulaben]

On mine both the switch and pressure sender (to the dash) are right next to the oil filter.

https://www.dropbox.com/s/g4gruu0bndnw3il/Indmar engine oil pressure sensors.jpg?dl=0