ECM Recalibration and Hunting

[Ray Isaac]

Everyone,

I recently did the ECM recalibration on my 480CE’s and it definitely improved my idle quality and throttle response. After doing the ECM upgrades I experienced RPM hunting on both engines so I did the fuel rack friction adjustment. The Port motor responded perfectly to this but the SB motor still hunts when cold but settles down when warmed up. I’ve tried to fine-tune the adjustment and I think I’m in the “sweet spot” since any adjustment in or out makes it worse when cold. Am I missing something in the adjustment process or will I need to live with the cold hunting?

Topic

[Ray Isaac]

Update: Still Hunting

Update: The SB motor went back to hunting again until warmed up. I’m lost as to why and not sure how to correct it. As I’ve posted I’ve adjusted the friction screw both ways and while it solves the issue temporarily, the next time I run the motors cold it hunts again. If I understood the mechanics of the adjustment I could possibly make an informed adjustment vs. just trial and error. Does anyone know what the adjustment physically does or what else I could adjust?

[Ray Isaac]

Tony,

‘Thanks for the reply. Ironically, the hunting cured itself after a few trips out at cruise speed and WOT. I’m guessing it needed to take a set at the new calibration of the friction plate. <br />Ray

[Tony Athens]

Ray, from your post and the work you have done. you are most likely way ahead of me messing the the 480CE and dealing with it’s quirks..

Good job..

[Author]

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