480CE idle/stumble/stall upgrades

[Ricky Shaneybrook]

I have 480 6cta 8.3 m4. My port engine stall as you engage into gear moving forward or reverse. If you bump the shifter several times to get the props spinning then it will go into gear without stalling   I replaced the ecm thinking that would fix it but it did not. Once the boat is moving there are no issues until you put back in neutral and try to engage back into gear.  Any ideas what else could be causing the stalling issue?  Thanks for any help Ricky

Topic

[Tony Athens]

Stall Stumble Issues

This a list of the ECM “fixes”

 

 

[Nel Martinez]

verify last version of software

I had this issue when I got my ecm reflashed by Cummins,.  They did not put the latest version on the ecm.  The start stumble problem began and it took me forever to figure it out. 

 

I took it back to cummins and they charged me 400 bucks to reflash it again. 

The ecm may not have the latest version even if it was new.  Hope it helps.

[William Walter]

Stall stumble

RS I also have a 480 ce.My engines idle at 600 exactly. I do have a slow idle button which brings the idle to 550.Typically I use this only when engines are warm.Tiara warns that the engines could stall at this rpm and it should never be used for docking.So I would think if your idle is too low it could be an issue as Steve said. I have never had the engines stall though at 550 when shifting but it is a possibility I think mostly when cold.Bill

[Steve Lewis]

RS,

Just for clarity,  Did this problem just appear or has it been going on for a while?  This happens all of the time or only if engines are cold?  What is your idle RPM?  Out of curiosity what are your trans ratio and prop dimensions? Wondering if an adjustment to idle rpm might help?

I have the 480CE’s and mine idle at 600port 620strbd.  When I shift into gear they momentarily drop to 580ish and then come back up.  I have 1.77 gears and 23x25props.

 

[Author]

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