Tunning AFR/VE question for engine breaking
Posted: Fri Aug 25, 2006 2:34 pm
Hi all,
I had my engine (Landrover aged and used V8 215ci port injection) fired last Friday with MS V3+MSII+Relayboard (latest code and MT2.25).
Everything perfect including IAC. I used a WBO2 LSU from TE, same... almost perfect unless 0.4 AFR delay in between MS and TE display (even if sharing the same power and ground and WB lin).
But during tunning effort (thanks Eric for the autotune and Phil for the VE analyzer) I had an issue with few points in very low kpa and high rpm, ie during very strong engine breaking).
I used a very long incline down hill for the purpose and I found to stay in the target AFR of 13.9 a VE of about 200 @ 2100rpm/19kpa.
The AFR reading is really stable during this engine breaking, so you can exclude transitory reading. My engine is iddling @900-950 rpm and 30kpa.
Other than that..I need to work on the Acc Enrichment... will be done.
I simply would like to know what I did wrong or if this is comming from the UEGO, the engine... or to my misunderstanding of the engine tuning in this region.But the engine was firing the exhaust in this region on carb and doing the same on EFI if I go above AFR 20/21... with far less engine breaking than I have for now... and no more exhaust detonation.
I attach the msq (log... sorry not for the latest session as the laptop fuc... up) but from the previous one with a bit less VE and highest AFR due to the limitation on UEGO correction of about 10%, the latest VE give 13.9/14 AFR.
Many thanks to Bruce, Al, Lance, Eric, Phil.... and all that contribute to this MEGASQUIRT feature... that's a great thing.
Bye
Eric
I had my engine (Landrover aged and used V8 215ci port injection) fired last Friday with MS V3+MSII+Relayboard (latest code and MT2.25).
Everything perfect including IAC. I used a WBO2 LSU from TE, same... almost perfect unless 0.4 AFR delay in between MS and TE display (even if sharing the same power and ground and WB lin).
But during tunning effort (thanks Eric for the autotune and Phil for the VE analyzer) I had an issue with few points in very low kpa and high rpm, ie during very strong engine breaking).
I used a very long incline down hill for the purpose and I found to stay in the target AFR of 13.9 a VE of about 200 @ 2100rpm/19kpa.
The AFR reading is really stable during this engine breaking, so you can exclude transitory reading. My engine is iddling @900-950 rpm and 30kpa.
Other than that..I need to work on the Acc Enrichment... will be done.
I simply would like to know what I did wrong or if this is comming from the UEGO, the engine... or to my misunderstanding of the engine tuning in this region.But the engine was firing the exhaust in this region on carb and doing the same on EFI if I go above AFR 20/21... with far less engine breaking than I have for now... and no more exhaust detonation.
I attach the msq (log... sorry not for the latest session as the laptop fuc... up) but from the previous one with a bit less VE and highest AFR due to the limitation on UEGO correction of about 10%, the latest VE give 13.9/14 AFR.
Many thanks to Bruce, Al, Lance, Eric, Phil.... and all that contribute to this MEGASQUIRT feature... that's a great thing.
Bye
Eric