2003 Utopia Cant rev above off idle

[levani041491]

Good Morning , just bought 2003 Utopia 240 EFI ( I guess new style) that was seating for 3 years , boat started and was running fine on the hose So we Sent it to have Complete seats/interior redone . 2 weeks later got it back but would only run on carb cleaner . I changed water separator filter/start plugs , still would not start so I took apart Complete fuel pump tank and was full off Gel looking fuel and oxidation so I cleaned everything and assembled it together . boat started on its own , started running Great , next day I tool it out in the water , ran fine for 15 minutes then I felt little misses and then is started popping backfiring from exhaust( light ) but would partially clear up after 4500-5500 rpms then Bang and it turned off and would not crank but I could spin the motor by hand , found negative terminal gave little wiggle and it started right up with running rough misfiring , started heading home and 2 miles later out of nowehere everything cleared up and started ruining Great like it never ran ( sounded like nice 4 stroke) came Close to Bridge dropped speed to 5mph ( no wake ) and when I try to accalarate from 1000rpms boat did not wanted to rev up at all , barrley running 800rpms and popping exhaust and misfiring and stalling . called tow and he got us home . at home cranking it would backfire and try to spin backwards so broke complete starter and 1 tooth I


I checked
New starter ( cranks great )
fuel Pressure its in spec
changed Map sensor top of the intake ( new)
checked fuel, no water fresh 89 octane ( filled it up before takeing it out )
new Spark plugs where covered in oil so I burned out and they spark fine
checked spark in all 6 cylinders and they all fire fine
FOUND PUDDLE OF OIL BOTTOM OF THE INTAKE ( dont know how it got there)

Got boat to start and Idle somewhat fine 15 minutes or so ( on the hose) after cleaning oil and spark plugs but when I move leveler forward it will start pupping puffing and wont rev past 800 rpms , I can move throttle WOT , I see throttle plate fully open wont rev just making lots of noise from intake and popping from exhaust like slow motion anti lag system



please advise me if there is else something I can check , i have DMM and power probe and all other tools that mechanic could have

 

[Dr Honda]

Off the top of my head... it sounds electrical since it's very random. Also... the backfiring is from random spark. I would start looking for a few things.

1) Bad lanyard switch. I would simply unplug it, and check the running.

2) Bad key switch. It's a little harder, but use your meter, and check while tapping the switch. Hopfully you will see if the contacts are going bad.

3) Check for a throttle guardian. It will be a small gray box, normally in the helm, and it's an RPM limiter. It does a bunch of goofy stuff when it goes bad. Nice thing is... if your boat still has one... just cut it loose, and toss it in the trash.

Along with that... check around the engine... especially the flywheel for chaffed, and broken wires. And finally... yes, you should have a gen2 engine... but post a pic so we are sure. If it's a gen 1... I'm going to guess you have a busted trigger. But a gen2 uses something different.

 

[levani041491]

I can’t find governor in helm , lanyard is good because unplugged it won’t start . Looks like crank position sensor little worn out since new belt been rubbing it little

 

[levani041491]

I just came inside , used 4 channel lab scope ( Maximus elite) to swipe tps and went from .5 volts to 3.8 volts , activates all 6 injectors at the time with power probe ( ecu disconnected ) and they are all spraing ( I hear it with throttle open )



After running it few minutes on idle , it cleared up and isles fine 1000rpms and 95% healthy , but as soon as I hit throttle it’s like hitting rev limiter in the car or 2 step launch control in slow motion , dumps fuel but ignition just does not let it rev up starts smoking and when I put it back to neural it will misfire from excessive fuel few seconds and then starts idling good

 

[levani041491]

Here is serial number

 

[Dr Honda]

OK.... you have a gen2. Put that in your "Watercraft" line. Then in the future, we will know.

When I was talking about the lanyard... I didn't mean to pull the lanyard.... I meant to pull the wires off the back. (Remove the switch from the system)

BUT... with your description that it's a "Launch control or rev-limiter"... then that's what we need to look at.

Check the crank trigger. about 350 ohms.... then watch for a voltage pulse while someone turns the flywheel (manually).

Oh.... put a volt meter on the battery, and start the engine. Then, rev it up. If you have a bad voltage regulator... and the voltage goes high... the system doesn't like that. The other way to test it is to disconnect the regulator, and run the engine. The other thing it can be doing, is passing AC. The computer doesn't like that either.

The ECU does limit the RPM if the TPS is bad... if the engine is overheating... if the fuel is low... or the oil pump is failing. (Never heard of that happening yet)

So... start at the top, and work down.

 

[levani041491]

Alternator is getting very hot but I will check the voltage

Crank position sensor has 2.2 mega ohms resistance and generates 1 volt while cranking the engine

 

[Dr Honda]

2.2 Meg is way out of spec as I recall.

****EDIT****

Yep... 320 to 350 ohms. Buy a new pickup.

 

[levani041491]

Today after removing its reading little different and I attached readings for Ohms , mega ohms and kilo ohms . When I replaced map sensor before it was same part number as Gm . Is crank sensor same as any car sensor out there? Something I can buy at advance auto parts ?

 

[levani041491]

Bought new sensor , new sensor had 312ohms . Replaced sensor and it started like a whole new boat . Thank you for Dr Honda for all your help

 

[Dr Honda]

Glad it worked for you. Hope you can enjoy the last few weeks of summer with it.

 

[dblackstone]

Bought new sensor , new sensor had 312ohms . Replaced sensor and it started like a whole new boat . Thank you for Dr Honda for all your help

Isn't it awesome to be able to get info that solves the problem without breaking the bank having a mechanic just spend money trying to fix things! This site is a great resource!

 

[Mikum1968]

Off the top of my head... it sounds electrical since it's very random. Also... the backfiring is from random spark. I would start looking for a few things.

1) Bad lanyard switch. I would simply unplug it, and check the running.

2) Bad key switch. It's a little harder, but use your meter, and check while tapping the switch. Hopfully you will see if the contacts are going bad.

3) Check for a throttle guardian. It will be a small gray box, normally in the helm, and it's an RPM limiter. It does a bunch of goofy stuff when it goes bad. Nice thing is... if your boat still has one... just cut it loose, and toss it in the trash.

Along with that... check around the engine... especially the flywheel for chaffed, and broken wires. And finally... yes, you should have a gen2 engine... but post a pic so we are sure. If it's a gen 1... I'm going to guess you have a busted trigger. But a gen2 uses something different.

Dr. Honda,

I'm new to the forum so apologies if this post runs afoul of decorum.

I have a 2001/2 Utopia and it's hard to start. Like other postings, I need to turn the wheel to kick in the higher rpm low speed turning function for a bit until the boat earns up a bit.

Other than air and fuel pressure (, thank you), is there anything else I should be checking out?

Another odd bit, at WOT the engine appears to throttle back automatically when I engage in a turn. Is this normal?

And, I see tithe key switch has come a push in feature for the choke (apologies if I am wrong about this), is there a starting procedure I should be following?

And, there appears to be a a lot of play in the throttle from neutral until the engine revs up. Is this normal?

Anyway, I'm going to disassemble the throttle and reassemble with new lubricant, trying to smooth out some sun damage to the plastic.

Otherwise the engine seems to run great.

Do you think I should pay particular attention to lubricating any cables or other components?

I'm in Las Vegas.

Thank you.

Michael