Engine Help Please

[purplehayes]

Hello folks,

This is my first post. I recently purchased a used 2002 Searay Amberjack 290. I have been getting some intermittent issues with the port engine so thought I might post it here to see if the experience of others can help me get an idea of what is what.

Ok... The boat though being a 2002 has only 260hrs on each engine (roughly) that is from the digital readout from the device directly attached to the engine.... ok so the issue.

The engines ran fine when I brought it home, the next night I took it out for a short run, when we dropped the crab net the port engine stalled. It started again with no worries and continued to idle just fine afterward, we then made a small run to drop anchor but it was fine there as well. After we started it up again and brought it in it stalled on me 4 times... or tried to twice I recovered it with throttle, the other two it recovered just fine on it s own...

Today, I ran it to check it and it stalled but not fully down to 300rpm but recovered.... then the mechanics looked at it and we changed the fuel filters and added some fuel stabilizer. I idled it back to the marina where it was sort of funny but did not stall.... the rpm's were a bit sporadic.

Anyway took it out later in the afternoon and the engine stalled again after running for about 20min at low rpm... then I had some issues with the belt but that is not related... Took it out and ran it keeping it out of the idle range while fishing and then brought it back in where it stalled about 4 times needing throttle to recover it while trying to park it... after we were parked pretty much then it was fine....sat there at idle for over 5 minutes while I cooled them down before shutdown.

Ok so that is the history... I am thinking it is something to do with the fuel and the mechanic guru thinks that I need to run a few tanks of gas through it.... so, is it purely cause the engine has not been run much in the last couple of years and I am now running it or is there some other issue.... the computer hook up said that there was nothing wrong with it, in fact it idled fantastically at the shop for 5 min with the system hooked into it... didnt move more than 20rpm from the idle commanded rpm.

OK, if you have read this far THANK YOU, thoughts please.

Cheers

 

[sprink56]

From a distance I am thinking perhaps a loose electrical connection somewhere that is grounding out or breaking circuit for a split second...then your throttle movement causes a re-connect.:huh: This loose connection might even be at the helm in the switch circuit...might even be a bit of corrosion.

Might be worth a look.

Good Luck and let us know what you find.

John F

 

[purplehayes]

Hi John,

Thanks for that, I had thought about electrical but only at the engine not at the throttle. I will ask them what they think about it when I take it in for new belts.

Cheers

Ron

 

[Fun Times]

For starters I would recommend that you should have your techs check out your idle air control (IAC) on the engine.

Also have them clean the throttle body on the engine.

Has a tune up been done at all to the engine since 02? Cap, Rotor, Check spark plugs, ect.:wink:

Good luck.

 

[tbirdvet]

I agree, sounds like IAC.

 

[BonBini]

From your description, it sounds like the engine slowly looses rpm until it dies. I’m assuming it’s not dropping a cylinder or anything like that. Your Tech seems to think the gas is fouled.

1)… pull filter and pour out to check for water. Before putting filter back on, dope it up good with some fuel injector cleaner of your choice. Do this for both engines.

2)… as the “Boat Tech” recommends; clean the throttle body. Some carb clean and a tooth brush works well. Do this for both engines.

3)… again as the “Boat Tech” recommends; Check on Tune up status. A Cap and Rotor should be replaced at start of each season. (cap has a moisture absorbent paper incorporated with in). At minimum put a new cap and rotor on each engine if haven’t been done already.

4)… now fire up each engine and throttle them up to clear the carb cleaner from the throttle body service. Let them run just long enough to get the injector cleaner that was poured in filter to the injectors. Shut them down and let them set a day or two.

1) - 4) should take care of a lot of maintenance related troubles.

IAC)... you could always swap out from Starboard to see if the problem moves!

Let us know how things are going…

 

[purplehayes]

Hey Guys....

Thanks for the replies and info.

I have emailed "the shop" and asked for them to order and schedule the cap and rotor, they were both recommended by the survey due to them being suspected as being original parts and with your suggestions here as well I am getting them changed as well as the belts for both engines. The belt on the port engine (suspect one) is also worn and at its maximum adjustments which we found out yesterday after having a secondary issue after a stall. (more on that later if it appears to be connected)

I know the plugs are new as is the oil and filters and we have replaced the fuel filters on both engines. We dumped them out on the port engine and had a look and the tech was happy to put it back on but the fuel went sort of milky after being out in the air for about 5 minutes or so.... so I got them to change the filters and added two fuel treatments to the tanks... my plan is to top up the tanks with "good" fuel and give the engines a bit of a run tomorrow but.... I will have a read of the manual and see about cleaning the throttle control myself before taking it out we will see.

As far as the IAC the tech said that after hooking the engine up to the diagnostic computer if there was a fault it should of indicated on that, and nothing was showing up including any real variance of the engines idle performance. It was commanding 600 and getting 612-630 so not bad.

Something which I thought of after the post and after chatting with the tech today was that the engine seems to only have trouble if it is in gear and bringing it back to idle after running it for a bit because if it is out of gear it is just fine..... now this is still to be tested by me but I will have a look at it tomorrow and if it tries to stall I will simply take it out of gear and test the correlation between the two to see if there is anything there.

What it comes down to is that the engine runs great at power and really all settings except for that below about 1000rpm after it has been run so I will see what happens.

Thanks again for the posts and I will keep everyone informed of any results and if a specific culprit can be found.

Cheers

Ron

 

[twomad]

had a buddys 350 mag fuel injected do the same thing and after a short time would not run at all and it ended up being the electrical part which is inside the distributer below the rotor can't remember the name of the part{old age] but when it was replaced motor fired right up issue fixed. the part was and easy diy and cost about 80$

 

[purplehayes]

Hey Guys,

Just a quick one as a little update to see what you have to say.

I cleaned the Throttle Control Units today and noticed after taking off the air filter on the port engine that the IAC Muffler was missing. Is there any chance that this could be causing my issue?

I would be surprised but then again it is an "electric" engine in control anyway, so.... I have to be honest in that I do not know the relationship to the IAC and the operation of the engine and then subsequently how/if the muffler could cause any issues. (something which is open in google right now for me to learn)

Cheers

Edit: Ok so what I have "learned" is that the muffler should only be a factor if it is dirty and clogged up but if it is not present then there should be no related issue. Also, apparently later model engines (not sure how far back) will not show an error code for the IAC using the diagnostic computer... and some recommend having a spare IAC on the boat or in the tool box as apparently they dont last very long.

Ron

 

[Redhook98]

Same issues with my AJ. It was an IAC..... I chased this issue for a long time, and thats what it was.

 

[purplehayes]

Hey Guys,

I will be changing the IAC tomorrow morning and then take the boat for a run. Just a quick "rookie" question: The IAC that I bought is all silver aluminum I assume this is the normal state of a replacement part or if it was directly from Merc would it be the black sort of rubber coated part. Or is that coating only on the factory "new" engines and subsequently indicating that the part is from initial build? I assume there is no coating available which I can put on it later that would match the rest of the engine... and I also assume that the coating on the engine is an anti corrosion coating??

Sorry for the "basic" questions, I will post the results tomorrow after the engine run.

Cheers

 

[Redhook98]

Get a can of Mercury Phantom Black spray paint. That will make it all better....

 

[purplehayes]

Lol, ok :huh:

Sort of answers my somewhat ambiguous question anyway... the part is the right one for the boat.

Cheers

 

[purplehayes]

:grin:

Just a quick update. As you all suspected the IAC was faulty. Once I got it off and looked inside it was all gummed up and looked like it had about 10% of normal mobility based on the clean areas.

None the less the new one works great and as per the sea test it seems to have the problem fixed.

Thanks to all for the suggestions, This forum has saved me a heap of time and money.

Thanks

Ron

 

[tcason]

Might want to consider a new mechanic if he did not diagnose the IAC valve from the start ....................

 

[purplehayes]

Might want to consider a new mechanic if he did not diagnose the IAC valve from the start ....................

I will consider this but unfortunately these guys are the Merc warranty guys in town so I would of thought that they were the "go to guys"...

I will see whom else is around in the merc'y waters.

Cheers

 

[tobnpr]

I'd pull the IAC and check it:

To check the IAC motor remove the unit, with the wires connected turn the key to the "on" position without starting the engine, the IAC should move in or out. If the IAC motor does nothing it has probably failed, replace it with a new unit and recheck system. Note: while the IAC motor is removed clean (use aerosol carburetor cleaner) the passages the IAC uses to control idle air speed, also inspect the IAC for a build-up on the seating (pointed) end and clean as necessary.

An engine that stalls at idle (car OR boat) definitely makes for some white-knuckle days...hope you get it figured out.

 

[purplehayes]

I'd pull the IAC and check it:

To check the IAC motor remove the unit, with the wires connected turn the key to the "on" position without starting the engine, the IAC should move in or out. If the IAC motor does nothing it has probably failed, replace it with a new unit and recheck system. Note: while the IAC motor is removed clean (use aerosol carburetor cleaner) the passages the IAC uses to control idle air speed, also inspect the IAC for a build-up on the seating (pointed) end and clean as necessary.

An engine that stalls at idle (car OR boat) definitely makes for some white-knuckle days...hope you get it figured out.

Hey There Tobnpr...

Thanks for the post... it was the IAC, I posted that a few posts ago but none the less thanks again for the suggestions.

Cheers