I have a 2008 Formula 370ss with twin 496 mercruisers.
We went for a ride today and the engines started fine 3 different times. The port motor now won't start, it turns over but won't start. I decided to spray a little starting fluid in the spark arrestor and it started right up and runs fine. Once I turn it off it will restart again unless I let it sit for 15-20 minutes then it won't start again.
I tried replacing the iac control valve and the camshaft position sensor and the fuel filter.
I had this message on the vessal view however once I cleared the code it hasn't returned. "Engine crank/cam encoder is not working properly"
Do you have any other suggestions to try?

I have a 2008 Formula 370ss with twin 496 mercruisers.
We went for a ride today and the engines started fine 3 different times. The port motor now won't start, it turns over but has a constent alarm sound and but won't start. I decided to spray a little starting fluid in the spark arrestor and it started right up and runs fine. Once I turn it off it will restart again unless I let it sit for 15-20 minutes then it won't start again.
I tried replacing the iac control valve, camshaft position sensor, crankshaft sendor, all the spark plugs and the fuel filter.
I had this message on the vessal view however once I cleared the code it hasn't returned. "Engine crank/cam encoder is not working properly. I also checked the fuel pressure and it was 41 pds on both engines. Anyone have any ideas what to try next?
Robert

Engine serial number?

What was the part number of the cam sensor you replaced?

Engine serial number is 1A053342

I don't know the part number for the can sensor, I have 2 engines in my 2008 Formula 370ss so I swapped it for the good running motor.

Sounds like fuel related if you spray starter fluid in and it runs.

Check for 5V power on the gray wire (5V ground is Black/Pink)
Use a digital meter

I checked it and it reads 4.98v

The 4.98V is within limitations of a meter, should see 5V

Need to get the motor scanned for codes

Things that can give a constant alarm are
ECT- overheat
Low oil pressure
Port or Starboard EMCT circuit overheat
Over speed

Will it start if its given a little throttle?

Edit: Do you see at least 300 rpm when ranking?

No it will not start if I give it a little throttle, the only way for it to start is if I give it a blast of starting fluid. I started it a few minutes ago and ran it for about 15 minutes to warm it up, after turning it off it would start right back up twice, upon the third try it wouldn't start again.

When the key is turned ON and pressure builds, does it stay there if you don't go to crank?