2003 6.2 Bravo going into guardian mode with no alarms

[Great lakes pirate]

So we took a trip last week to catch a ball game in Detroit. The boat ran great all the way there. On the way back we ran into some 10 footers and sleet. I also could not get the starbord engine to rev up when I wanted to get on plane. With that being said we decided to turn back and tie up and wait for better weather to bring the boats home.

The week before I changed plugs, wires and distributers. The oil reservoirs are full and the engine oil is full. The oil pressure was OK and so was the engine temps. I am not getting alarms so I am a little confused as to why the one engine will not wind up:huh:. I think a rinda code reader will be in my near future. I have read as much as I could find on this site but still don't know what to look for next. My engines have the ECM555 system.

Any other suggestions would be helpful.

 

[jason78]

Did it say what % your power was reduced to?

Edit: I just noticed it is an 03 so unless you added them, I am guessing you would not have SC1000 gauges or a way to see the % drop in power.

 

[Great lakes pirate]

Jason, you are correct. I dont know what % the power was reduced to. I am not even sure what RPM I was limited to because I was to busy fighting the waves.

 

[jason78]

Jason, you are correct. I dont know what % the power was reduced to. I am not even sure what RPM I was limited to because I was to busy fighting the waves.

In that case I am not sure how to determine this without a scan tool. Personally, I recently ordered the Rinda software and can't wait to use it. Too bad I don't live closer.

Reason I was asking about % reduction is I have the ECM 555 manual and I think it has a table that shows X% will be available with X kind of alarm. I will check the manual tonight and see if there is any information I think could help you.

When was the last time you changed the impeller on that engine? Have you checked the Water PSI on that engine? A possibility could be Low Water PSI caused by bad impeller or sensor.

 

[Alex F]

.... On the way back we ran into some 10 footers and sleet. I also could not get the starbord engine to rev up when I wanted to get on plane. With that being said we decided to turn back and tie up and wait for better weather to bring the boats home.

The week before I changed plugs, wires and distributers. The oil reservoirs are full and the engine oil is full. The oil pressure was OK and so was the engine temps. I am not getting alarms so I am a little confused as to why the one engine will not wind up:huh:. I think a rinda code reader will be in my near future. I have read as much as I could find on this site but still don't know what to look for next. My engines have the ECM555 system.

Any other suggestions would be helpful.

I had similar issue on my 240DA. One wire came loose off a spark plug. It wasn't noticable at lower speed, but when I wanted to get on plane it would refuse. Check all the wires on plugs and the caps.

Also, when was the last time you changed the fuel filters, maybe they're due?

 

[Great lakes pirate]

In that case I am not sure how to determine this without a scan tool. Personally, I recently ordered the Rinda software and can't wait to use it. Too bad I don't live closer.

Reason I was asking about % reduction is I have the ECM 555 manual and I think it has a table that shows X% will be available with X kind of alarm. I will check the manual tonight and see if there is any information I think could help you.

When was the last time you changed the impeller on that engine? Have you checked the Water PSI on that engine? A possibility could be Low Water PSI caused by bad impeller or sensor.

Just orderd the scan tool. Should have it by Friday. I changed the impellers at the start of last season. They have about 80 hours on them. I dont have smartcraft screens so I dont know what the PSI is.

The engine wot RPM is about 5K, the more I think about it I remember only being able to achive 2500 so it capped me out at 1/2 of WOT.

 

[Great lakes pirate]

I went back to Detroit last night and checked all of the connections at the plugs and the distributers. All was snug. One thing I did notice was that the serpintine belts were not routed the same port to starbord. I dont think this would cause a problem but when I go back to run the boat home I will make sure both belts are routed properlly. I changed the water seperators in April but have never changed the fuel filter itself.

 

[jason78]

OK, again I was not thinking about you not having the SC gauges to check the PSI. It has been a long day.

That scan tool will be a great investment. I 'll look tonight and see if I can tell what all conditions would cause a 50% reduction.

Jason

 

[Alex F]

I went back to Detroit last night and checked all of the connections at the plugs and the distributers. All was snug. One thing I did notice was that the serpintine belts were not routed the same port to starbord. I dont think this would cause a problem but when I go back to run the boat home I will make sure both belts are routed properlly. I changed the water seperators in April but have never changed the fuel filter itself.

Ok, in this case let's look at the obvious and simple stuff. Does the engine able acheave higher RPMs when it's in neutral?

My 320 was very sensetive to clightly clugged scoopstraners and/or seastrainers after passing pouch of ealgrass/seagrass. I know you have outdrives, but you can also pick something on them as well.

BTW, 80hrs and just over a year on the impellers doesn't mean they're perfectly fine. Mostly it depends if they were ever introduced to any obstraction like silt or sand in shallow waters. Only you know the answer to this. Having said that, one can damaged perfectly new impeller very fast. I don't mean that you have to run and replace it, but don't just rule out the posibility of poor sea water circulation.

 

[Lazy Daze]

Fuel is good thought - all that bouncing around could've jarred some crap loose in the tank and/or lines.

Did you check the props? Maybe you've got something caught.

 

[Great lakes pirate]

Ok, in this case let's look at the obvious and simple stuff. Does the engine able acheave higher RPMs when it's in neutral?

My 320 was very sensetive to clightly clugged scoopstraners and/or seastrainers after passing pouch of ealgrass/seagrass. I know you have outdrives, but you can also pick something on them as well.

BTW, 80hrs and just over a year on the impellers doesn't mean they're perfectly fine. Mostly it depends if they were ever introduced to any obstraction like silt or sand in shallow waters. Only you know the answer to this. Having said that, one can damaged perfectly new impeller very fast. I don't mean that you have to run and replace it, but don't just rule out the posibility of poor sea water circulation.

When in neutral I can achive higher RPM's. I do boat in skinny waters so it may be true that sand has chewed up a impeller. I can't think of a way to determine the water flow through the engine. My water temp gauge never ran high so, I don't think the flow/pressure is low. But... I am no expert.

 

[Great lakes pirate]

Fuel is good thought - all that bouncing around could've jarred some crap loose in the tank and/or lines.

Did you check the props? Maybe you've got something caught.

I am going down tonight and will check the props. That is a very good sugesstion.


Is it ok to run the boat home 30 miles with my port engine at cruising/planing spees and my starbord at 1500 RPM just to get 'er home?

 

[Presentation]

I am going to suggest that your engine is not in guardian mode and a code reader would show nothing.

Did you install a sierra rotor and cap or merc? Sierra is having some known issues.

My suggestion is to put your old Merc distributor cap and rotor back on the issue engine then see if this resolves the issue.

 

[Alex F]

When in neutral I can achive higher RPM's. ....

I think this is your biggest clue. IMO, you have two possible issues:

1. Engine issue is present only under load.
2. Engine is fine, but oudrive is preventing for the engine to operate.

I would first inspect the drive. Make sure the props are ok and the water inteake is free of obstraction.
BTW, did you ever service your drives? If yes, when was the last time?

IMO, if you had issues with prop you would feel vibration. If there's no vibration, most likelly your props are fine. They don't go bad unless you hit them. So, if you didn't have groundings or din't hit any objects the're fine. In this case seagrass is the only possible contributor (assuming there's no issue with the drive).

I am going to suggest that your engine is not in guardian mode and a code reader would show nothing.

Did you install a sierra rotor and cap or merc? Sierra is having some known issues.

My suggestion is to put your old Merc distributor cap and rotor back on the issue engine then see if this resolves the issue.

Hey Doug,

Would this Sierra issue be possible if he has no problem getting high RPMs in neutral?

 

[Great lakes pirate]

I am going to suggest that your engine is not in guardian mode and a code reader would show nothing.

Did you install a sierra rotor and cap or merc? Sierra is having some known issues.

My suggestion is to put your old Merc distributor cap and rotor back on the issue engine then see if this resolves the issue.

Not sure what brand my mechanic used when he replaced the distributer. I still have the rotors in a box and will install when I get back to my slip. I don't want to snap the bolts off that hold the distributer. The boat ran great on the trip down so I think the distributer is ok??? I dont have the old distributers any longer.

 

[Great lakes pirate]

I think this is your biggest clue. IMO, you have two possible issues:

1. Engine issue is present only under load.
2. Engine is fine, but oudrive is preventing for the engine to operate.

I would first inspect the drive. Make sure the props are ok and the water inteake is free of obstraction.
BTW, did you ever service your drives? If yes, when was the last time?

IMO, if you had issues with prop you would feel vibration. If there's no vibration, most likelly your props are fine. They don't go bad unless you hit them. So, if you didn't have groundings or din't hit any objects the're fine. In this case seagrass is the only possible contributor (assuming there's no issue with the drive).

There is no vibration. I had all 4 props tuned over the winter. Ill check the intake for blockage. I had both carrier bearings replaced as well as seals over the winter. I also had skegs welded on.

 

[Alex F]

I think this is your biggest clue. IMO, you have two possible issues:

1. Engine issue is present only under load.
2. Engine is fine, but oudrive is preventing for the engine to operate.

I would first inspect the drive. Make sure the props are ok and the water inteake is free of obstraction.
BTW, did you ever service your drives? If yes, when was the last time?

IMO, if you had issues with prop you would feel vibration. If there's no vibration, most likelly your props are fine. They don't go bad unless you hit them. So, if you didn't have groundings or din't hit any objects the're fine. In this case seagrass is the only possible contributor (assuming there's no issue with the drive).

There is no vibration. I had all 4 props tuned over the winter. Ill check the intake for blockage. I had both carrier bearings replaced as well as seals over the winter. I also had skegs welded on.

Ok, let's summarize our facts:

1. Engine was serviced and is able to get to high RPMs when in neutral.
2. The drive was serviced.
3. Props are tuned and look good.
4. When you put her in gear you get max 1500RPMs.

Based on your original post I understand that the boat ran fine and something just happened all of a sudden. Is this correct? What are other symptoms other than just lack of RPMs?

 

[Presentation]

Not sure what brand my mechanic used when he replaced the distributer. I still have the rotors in a box and will install when I get back to my slip. I don't want to snap the bolts off that hold the distributer. The boat ran great on the trip down so I think the distributer is ok??? I dont have the old distributers any longer.

You will need a paint pen, a torque screwdriver (looks like a star on the tip) or a cheap ratcheting torque kit works great plus your old rotor and cap.

For better access to the rotor and cap remove the big black plastic engine cover. No tool needed, just turn the black knob with your hands.

You will see 9 big wires that all go to the distributor cap.


Number the wires. A paint pen works great for this. Don’t worry about any fancy numbering system, just number them in the order you will understand.

Grab one boot on the end of one of the wires, turn the boot in one direction then turn it the other direction then pull the wire off as you are turning the boot. Repeat until you have all 9 wires removed. Pull the boot, not the wire.

Using a torque screwdriver remove the two torque screws on the cap. The screws come off easy.

Pull off the cap.

Remove two more torque screws on the top of the rotor. Pull off the rotor.

Put the old rotor back on. It only fits one way, you can’t mess it up. Put two screws back on the rotor, just snug them up, don’t get these screws on crazy tight.

Put the cap on, again, put the screws on snug.

Reinstall the wires. As you push the wire on you should feel a pop.

Start it up and see if your problem is gone.

Please post a follow-up and let us know what happens. Thank you!

 

[MasterFab]

The previous posts concerning the cap/rotor are correct, and this is an easy fix if it solves the problem. If not, I would go right for the fuel filter. You did indicate the problem manifested after slogging through some pretty rough conditions, and this is exactly when any loose crap in your tanks would wind up in the filter, clogging it to the point that full power is not available, but reduced power is. Change the fuel filter(s), see what happens, and let us know!

Good luck with it.

Dale

 

[Great lakes pirate]

Ok, let's summarize our facts:

1. Engine was serviced and is able to get to high RPMs when in neutral.
2. The drive was serviced.
3. Props are tuned and look good.
4. When you put her in gear you get max 1500RPMs.

Based on your original post I understand that the boat ran fine and something just happened all of a sudden. Is this correct? What are other symptoms other than just lack of RPMs?

Yes the boat ran fine 2 hrs down and 1 hr. (idle speed up river prior to entering the lake and no more no wake zone). Seems to achive closer to 2000 - 2500 rpm. It was a very cold damp morning also. Other than lack of power it does take a little bit of throttle to get the engine to fire up. It does Idle once it starts. I replaced both IAC mufflers in April and have a spare IAC but have not installed it yet on this engine.