Sea doo sportster stalling when pull to idle

[Scubadave16]

I have a 2005 Sea Doo sporster with the 3 cylinder 4 tec engine. It has been running fine until just recently when it starts stalling out when i pull the throttle back to idle. it typicaly does this after i have run it a while not usually when pulling away from dock. once it stalls it is somewhat difficult to restart, but after 15-30 seconds it does restart. I maybe? smell a little gas when it restarts but not definite. once it starts up it seems to be OK but then when i pull all the way back on the throttle say to dock it it will stall out again. no hesitation, no knocking, no backfire; just quits.

some info. I keep it in the water all the time. I have in fact pulled a ton of weeds into the intake and have to pull em out several times a day. I put new spark plugs in last spring. the boat has always had an annoying surge at certain RPM which i am led to believe is pretty much standard with this model.

the gas is still the first fill from mid May since I haven't used it very much this year (sadly).

any help would be appreciated.

 

[Browsing]

Is the throttle cable nice and responsive? If there is some slop in it, it could cause your throttle body to close when backing off the throttle and starve the motor of air, shutting it down. Honestly, it sounds like a fueling issue especially if you’re getting a slight fuel smell upon startup. Is there a fuel filter you can replace?

How does it idle when you start it up and leave the dock initially and when pulling back in?

 

['07 Challenger]

Even if the throttle cable has a problem, the throttle body can only close to the normal idle position so it's definitely not that.

My first guess is that the coolant temperature sensor isn't working right and making the ECU think that the motor is cold when it's actually at full temp. Just a guess, there's too many possibilities. That could also cause the surging.

 

[Scubadave16]

Even if the throttle cable has a problem, the throttle body can only close to the normal idle position so it's definitely not that.

My first guess is that the coolant temperature sensor isn't working right and making the ECU think that the motor is cold when it's actually at full temp. Just a guess, there's too many possibilities. That could also cause the surging.

well i wonder if you are on the right track because it did it again today in the harbor. I had filled up with fresh gas and put half a can of Sea Foam in the tank. It was running fine out on the lake except for the aforementioned surging at around 2000 and 4000 rpm. then it just died when i pulled the throttle back to idle from 2500 Rpm. the engine cranked briskly but would not start at all. nothing, just cranking. When i opened the engine compartment it seemed very warm. As most laymen do I stared at the engine for a bit but really not doing anything. after 5 minutes I tried again and it started up and ran fine. maybe it cooled down enough in that time period? I dunno.

 

[MacSeaDoo]

Idle air control is metered by the idle control valve when the throttle is closed. Next time it will not start, advance the throttle a bit and if it starts, your air control valve (ACV) is suspect.

The ACV is on the throttle body and is a servo type motor that operates an alternative air path around the closed throttle body. Often it becomes corroded or gummed up and fails to open.

 

[Scubadave16]

Idle air control is metered by the idle control valve when the throttle is closed. Next time it will not start, advance the throttle a bit and if it starts, your air control valve (ACV) is suspect.

The ACV is on the throttle body and is a servo type motor that operates an alternative air path around the closed throttle body. Often it becomes corroded or gummed up and fails to open.

dumb question... since on my boat the throttle only moves when it is in gear, how would i advance it more than just a tiny bit? I did move the gear lever into F and then could goose the throttle lever, but then the starter doesnt engage until the throttle lever is pulled to idle and the gear lever to N.

 

['07 Challenger]

I doubt it's the idle air control, but to test you could have a helper hold it at the engine, or put something on the throttle stop screw to hold the throttle open a bit.

 

['07 Challenger]

I just looked at the idle air bypass valve for these and it looks just like one used on a car that I found particularly troublesome. The upside is that they're fairly cheap. Maybe pull the connector off just to make sure there's no corrosion, probably not the problem, but should be an easy check.

 

[Scubadave16]

by any chance do you have a link to a picture of this ACV valve on the boat? I tried to google it but just have pics of the part.

 

['07 Challenger]

Amazon.com

From reading the first few 5 star reviews it appears that this might be your culprit. At a glance it appears to fit all 4-tec motors, but I didn't pay close attention so make sure it's right for yours.

 

[DAW67]

so I also have a stalling problem so asking this group if it may be the same issue. my 2003 GTX 4-tec was stalling when the throttle was released last couple of months. it started right up again and runs fine when the throttle is pressed. no gas smell though. new spark plugs this year and I treat the fuel with stabilizer. I've pulled it for the season and will winterize it (although will be in my garage). should I try to replace this air control valve? and can I test it out of the water if I hook it up to my garden hose (via the stern cooling system flush tube)?