- Fri Feb 14, 2020 6:32 pm
#40944
Guys,
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
etc...
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...
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
etc...
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...
BMW e30 m50b25tu & BMW e30 m40b18 turbo (in progress)