[jpuehl]

I have been noticing that on some, not all but I'd say about 50%, of my logs that the timing drops to almost 0* in the 3k rpm range. Below is a log of what I am seeing in other logs as well. The ign_2 - ign_6 values look ok in this log, as do the trims, AFR and fp_h values. I've read that the DME switches from "spool" tables to "regular" tables at 3500 rpm but I've looked at the tables that were changed in the BEF and none are parent to the cause of this. It doesn't happen all the time and I can't see a pattern in the logs. I CAN feel the car slowing during this RPM range as well so it'd be nice to "fix" this if possible.

[Dave @ BMS/Fuel-It!]

Hmmm..

Do you have a recent log where it doesn’t drop down to 0 or .8?

[jpuehl]

Originally Posted by Dave @ BMS/Fuel-It!

Hmmm..

Do you have a recent log where it doesn’t drop down to 0 or .8?

Dave,

Here's a log from the same "data logging" session where the timing doesn't drop that low. You can clearly see the timing drop from 14.4* to 3.2* just past 3k rpm with no indication why. I did recently "reload" the BEF to trying to "fix" this problem but it didn't make a difference. I have also reset adaptations almost every time I start a "data logging" session, which has been very frequently since my PS2 upgrade. I can definitely feel the car "nose over" when the timing drops like this, and pick back up afterwards.

The sparkplugs are new and coils are recent, fuel is 98 octane. The car runs great other than this timing issue.

[jpuehl]

Originally Posted by Dave @ BMS/Fuel-It!

Hmmm..

Do you have a recent log where it doesn’t drop down to 0 or .8?

I did some research and came up with a timeline, doesn't answer why this started happening however:

3/28/2020 : latest JB4 board installed & connected fuel pressure wires.
4/5/2020 (and prior): was using firmware version 17.
4/6/2020 : no logs so assume still on firmware version 17.
4/7/2020 : upgraded firmware to 18_T1 (for testing).
4/?/2020 : reset adaptations using MHD (may have been the cause of the timing issue, just don't remember exactly when I did this).
4/12/2020 : first time intermittent low/no timing showed up in 3k rpm range.
4/?/2020 : reloaded BEF trying to "fix" intermittent low/no timing issue, made no difference.
4/21/2020 : reloaded firmware version 17 (still have intermittent low/no timing issue).
4/22/2020 : upgraded firmware to 18_T2 (still have intermittent low/no timing issue) .

I also do a 1-4 adaption reset often when testing changes, I might need to stop this and see if the timing issues go away. Prior to 4/12/2020 the timing in the 3k rpm range was mostly great.

[jpuehl]

I think I have this issues resolved; I re-reloaded the BEF and the timing seems to be back to "normal", however I don't like the transition in timing between spool and normal, it seems like a pretty abrupt drop rather than a smooth transition.