2003 outback engine stall and high idle

Hey guys!
Well with boating season here, I finally got time to run the boat in the lake.
After sitting for 7 months, fresh gas and the boat fired right up.
I ran the boat this weekend and found that my issue I was starting to have last season is still present.
What happens is if I run the boat at 20-30 in the lake towing a ski'er and I throttle down and kick into neutral that my idle of the boat will stay quite high. If I kick it into neutral and the idle stays high if I go into a gear (forward or reverse) in the state we get a big clunk as it kicks into gear.
The other issue I had this weekend is a new one. I was towing a ski'er at about 25 and all of a sudden the engine completely stalled out, all electronics were on with no disruption. I turned the key off, and the boat fired up with no problem and ran fine. In driving the boat now I am listening to everything and I get a very random stutter almost like a misfire, but I don't know for sure.

Last season I changed out the spark plugs and distributor cap as a maintenance.

Any thoughts on either of these issues?

Thanks!

Carbureted or fuel injection?

How are your throttle cables looking and return springs (if present)? Any play?

Do you have PerfectPass? If so, is the servo motor behaving properly?

Definitely do not put it in gear if it is revving high - unless you are looking for more to repair.

Mine completely crapped out one night while towing a surfer. But completely crapped out - not a single light on anywhere. In a pitch black section of the river... Turned out to be a slightly loose main wiring harness plug. You might check not only for tightness and fully seated plugs but pull them apart and look for any corosion.

My PP servo motor also crapped out last year and had to be replaced. The joy of older boats!

Thanks for the reply

I'll have to take a look to to see if it's carb or TBI. I honestly haven't payed attention to it.
Throttle cables seem good with no sticking.
I do not have perfect pass

I experienced the out of nowhere "conk out" a couple of years ago. At first it would crank right back up but it soon began taking longer & longer. Although there could be any number of underlying causes, turns out my issue was a bad fuel pump. Given the similar symptom, you might give it the once over to make sure. Good luck.

I should mention my gas level was low but this was never an issue before.
I have never changed out the fuel filter I have owned it since 2018.
I'm going to bring a replacement filter with me next time I am at the cabin.

Is this located by the tank under the trunk? I have a water separator also at the front of the motor (left side).?

Or is that the fuel filter and I don't have an inline fuel filter ?

Carb engine I would check return springs on carb or vacuum leaks. Intake manifold leak will cause high rev idle and stalling.

Fuel injection I would replace the TPS (throttle position sensor).

Is there any specific way we can test for a vacuum leaks or an intake manifold leak?

Quote:

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Originally Posted by Dom08

Is there any specific way we can test for a vacuum leaks or an intake manifold leak?

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WD-40 - with engine running, spray around mounting surfaces and hoses. If the idle increases or smoothes out, that is your leak. The wd-40 acts like extra fuel and air into the engine causing it to rev up, or it will seal the leak temporarily and your engine will run better.

Amazing, I will do that. Thanks!


Any info on the fuel filter? And water separator?

I have a 2004 outback LS with the carbureted engine.The fuel filter is on the right side of the motor (looking forward).down under the motor mount.You have to look for it,its hard to see.

Are they just universal fuel filters(like an oil filter) or are they moomba specific?

Yea I have a filter on the front of the engine on the left side when looking towards the back of the boat. It's a clear filter where you can see in. I wasn't sure if this was a water separator or a fuel filter. I wasn't sure if maybe I had a remote fuel filter somewhere else (maybe by the tank at the trunk).

There is a wire harness at this filter/separator that if disconnected it will stop the engine front running.
I'm just trying to have the right things on hand as the boat is 3 hours away

The engine is TBI,
This narrows down to a possible TPS, and no potential vacuum leak which makes things easier.

Sure does!

The 2003 is PCM engine and is GM based. The TPS should be an easy part to source.

Quote:

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Originally Posted by Holdmybeer

Sure does!

The 2003 is PCM engine and is GM based. The TPS should be an easy part to source.

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Nevermind the PCM comment...you probably have the indmar assault.

Yep. I have an assault in it
I reached out to inboardonline and they pushed me to a 556082 part number for the TPS.
Is there a cross reference for these in GM? I believe it's a GM block. Or just stick with the true Indmar part? Cost is so high compared to a vehicle TPS ��

You may be able to find something but it most likely won't be easy. I went through a similar situation trying to get a new alternator and a new starter in mine a few weeks ago. After going to 4 parts stores and getting blank stairs from counter jockeys because I couldn't give them a year/make/model of something on wheels I finally gave in and ordered the alternator through skidim. I did luck out though and a really smart lady at Autozone was able to pull up a starter that fit a mid 90's GM C1500 and it was a perfect match. That happens about 1 in 1000 times anymore....

Yes - the Indmar Assault TBI is basically a mid-late 90's Chevy truck 350ci engine, slightlly modified. Some parts will interchange, sometimes.

Try AC delco 213-895

You should be able to go to a local auto parts and pick one up. The TPS isn't maritime changed but not sure if it is the same harness plug.

Thanks guys! I'll give it a shot!
Appreciate the help

Did anyone have any tips if there is an inline fuel filter by the gas tank or if it is a fuel filter/water separator at the front left of the engine when looking back at it

Most boats I have worked on the Filter is the canister style close to the engine. If there is a strainer on the fuel pump assembly, it only gets changed when the fuel pump is replaced. The in tank strainer keeps large particles out of the pump and is not a true fuel filter.

Thanks. Imm bring up a canister fuel filter with me!!