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Help with building your Speeduino, installing it, getting it to run etc.
By GhjEng

Just dropping this topic here to help anyone else that stumbles into this...

I just spent a couple days chasing a hunting idle, checking the usual suspects:
1.) Vacuum Leak
2.) Lean fuelling
3.) Dodgy IAC

Then, after looking at a log that I took, I saw that the DFCO (deceleration fuel cut off... in the accel enrichment page) was coming on, cutting fuel,--> causing rpm to drop... then when rpm dropped enough, it would switch fuel back on, causing rpm to rise, etc... and this presented itself as a hunting idle.

This wouldn't usually have been a problem, but my intake is a bit leaky, causing a higher rpm than usual... so I was getting into the area where DFCO was active...

By GhjEng
pazi88 wrote:So problem was just lack of tuning :D
:D Yeah, exactly... first tuning experience, so very silly mistakes. Just like you I’m very strong with electronics and control... have a mechanical engineering degree, worked in industrial automation, Mechatronics and robotics for 15+ years and I still make silly mistakes like this ;)

But again, thanks for all your posts, videos and work... big inspiration and a big help!

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