200 M2 Opti Hard Start- 03 Utopia 185

[nokwit]

Well I've read many many hard start posts for 240 efi's and others but didn't really find any for the 200HP Opti.

I purchased the boat this spring with a newer powerhead on it with about 140hrs. It wouldn't start the first time I tried to take it out on the water. It only had a single battery in it and seemed to crank slow so I installed a second battery as it had the holder and cables already there unused. I know these engines won't start if there's too much voltage drop. Took the boat out and it started up great. Then the next time it started great cold and then wouldn't start after docking it at the launch and backing the trailer in the water. Pretty frustrating.. The next trip it started right up cold and I docked it after launching and shut it off and then it wouldn't restart without giving it some throttle. It ran great after that until I docked it again at the launch. I thought maybe it was just some old fuel and starving for fresh air after a long run (I believe the 240efi's may have this issue) Now after a few more runs it's now hard to start cold or hot. You need to throttle it to get it to run and it normally takes a couple tries before you can let off where it will idle. So it's overfuelling and isn't starving for fresh air in the engine compartment as it's opened to turn on the batteries before launching and I even ran the fan.

Once it's running it seems fine. The top speed is only reaching 40mph but I've never been out where there hasn't been rough chop yet.


I had Merc G3 software hooked up previously and the only faults where for what I believe were smartcraft configurations which there's no smartcraft installed. I'm going to hook the Merc G3 tool back up tomorrow but I doubt I will see much.

Any solid ideas on where to start would be appreciated?

 

[Dr Honda]

Since it's a Di engine... there are a couple things that come to mind. Fuel, Air, compression. If the compression is low, then it will have a hard time starting wet. If either the air pressure, or fuel pressure is low... then it can't inject fuel into the cyl.


BUT... with your description... it also sounds like the injectors them selves could be leaking down, and flooding the engine.

Start with the 3 pressures, and we can move forward.

 

[nokwit]

Checked pressures.

- 20 psi on at fuel rail schrader valve with when lift pump runs at key ON. Manual states 10PSI. Still not sure how this would impact starting.
- Around 80 psi air pressure when cranking
- Gauge needle bounces between 80 and 90 while cranking while checking fuel pressure.
- It started up today when first testing after I installed the new fuel separator filter. I cycled the key several times to fill the filter before I cranked. However this isn't related as I can cycle the key as often as I want once after the initial start up and it doesn't help. It's not starving for fuel. It was just that the engine was cold.

- After it started up and I let in run for maybe 30 secs as I don't have the flushing hose hooked up for testing.
- Tried to start it after shutting it off and it would 'kick' but not quite start up.
- Gave it a tiny bit of throttle to open the butterfly. This didn't help.
- Decided to just keep cranking it with no throttle input and after probably 10 or 15 secs it will start, rev up and then die.
- Crank it with full or near full throttle and it will start up but I let off the throttle to not over rev and it dies out. I can normally get it to stay running after several attempts if it's in the water. I've had no success in keeping it running when it starts up at full throttle out of the water. I think due to the noise and no engine load, I'm simply closing the throttle too fast. In order to keep it running in the water, I close the throttle but not completely or it will die. I wave to work in back and forth a bit keeping it running before it will idle.

I think my next step is to check the vapor seporator?

Still trying to fully understand this fuel system.

 

[nokwit]

Checked pressures.

- 20 psi on at fuel rail schrader valve with when lift pump runs at key ON. Manual states 10PSI. Still not sure how this would impact starting.
- Around 80 psi air pressure when cranking
- Gauge needle bounces between 80 and 90 while cranking while checking fuel pressure.
- It started up today when first testing after I installed the new fuel separator filter. I cycled the key several times to fill the filter before I cranked. However this isn't related as I can cycle the key as often as I want once after the initial start up and it doesn't help. It's not starving for fuel. It was just that the engine was cold.

- After it started up and I let in run for maybe 30 secs as I don't have the flushing hose hooked up for testing.
- Tried to start it after shutting it off and it would 'kick' but not quite start up.
- Gave it a tiny bit of throttle to open the butterfly. This didn't help.
- Decided to just keep cranking it with no throttle input and after probably 10 or 15 secs it will start, rev up and then die.
- Crank it with full or near full throttle and it will start up but I let off the throttle to not over rev and it dies out. I can normally get it to stay running after several attempts if it's in the water. I've had no success in keeping it running when it starts up at full throttle out of the water. I think due to the noise and no engine load, I'm simply closing the throttle too fast. In order to keep it running in the water, I close the throttle but not completely or it will die. I wave to work in back and forth a bit keeping it running before it will idle.

I think my next step is to check the vapor seporator?

Still trying to fully understand this fuel system.

 

[nokwit]

Also there's no residual air pressure or fuel pressure immediately after cranking stops. Not sure if there's supposed to be any or not.

 

[Dr Honda]

It sounds to me like the fuel injectors are leaking, and it's causing your engine to flood after it gets shut off. It's a common thing, especially when the engines sit around. I would send them out to be serviced.

 

[nokwit]

Tested again this morning with new gauges. It started up fine. Shut it down. No start.

pressures appear to be within spec. I do get about 5psi residual pressure on the fuel rail. There's never any residual air pressure though. I don't believe there should be.

Is there any cleaner I can force into the rail that may help? Or are they like most injectors. If they are plugged you can clean but if they leak cleaning won't help.

 

[nokwit]

Is there any way to isolate each bank?

 

[nokwit]

I guess I can put regulated air pressure to the rail and see if it holds 80 psi pressure. if it holds it for a good length of time then I would think the injectors aren't leaking down.