[MattSkelton]

Couple of questions...

Most pressingly I am on the latest FW 202207.1 for my DIY-EFI Core 4 board, I am normally aspirated engine and all is quite good to be honest. I have worked out if i increase my fuelling at crank the car starts better. I have moved my IAT to the front of the engine to cut down warm temps from the engine. I am having random cut outs, usually when colder and when approaching a junction. Initially i thought this was a stall but it seems more electrical. The Fuel pump stays running and if i reach for the key it wont start unless i turn off then back on. The trigger filter is set at medium. Any ideas where to start hunting.... I thought i would run a log the other day when connected to the laptop, nothing happened of course.

Secondly i have a PID tune on my IAC i have a two way BMW type valve it settles ok but coming from speed down to idle the RPM drop to almost a stall before picking up. Where do i need to tweak next.

[PSIG]

Get those logs. Important info is there for guiding your tuning, and assisting our troubleshooting.

IAC is for general and slow changes in engine speed corrections, or only targets for warmup. I suggest employing more aggressive added Idle Advance to push decel recovery. Move best results to the Idle Advance function without over-speed retard initially. This will allow you to play with idle herding later. You'll get a feel for it, and if changing to Switching mode can work better than Added mode.

In order to find better settings, test for max effective idle timing (MBT) at your target idle. Let's say that's 32°. Enter 32° into the column directly below your idle rpm column, so as soon as it falls under target idle the added timing comes-in hard.

I prefer to begin with only using IAC for open-loop idle and warmup, so it doesn't "help" the decel rate when tuning idle timing. Or, close and disconnect IAC completely, using the throttle stop for base idle timing tuning so it isn't working behind my back. I don't want IAC to be pulling rpm down faster to where I want idle to stabilize, then try to recover overshoot. Rule-of-thumb — I turn off all automated functions (IAC, EGO_Corr, etc) so they do not fight me while tuning for best performance and response. I turn them on and tune them one-at-a-time when the system is ready for them (stable), and I know what to expect. Have fun!

[MattSkelton]

PSIG useful advice as ever.... I seem to have a flat line on my idle advance, i presume this is not good!

Screenshot 2022-11-22 204107.jpg (87.78 KiB) Viewed 1215 times

The MBT I take it that's different to the idle advance at idle? My car runs 10 BTDC for advance at idle. I have a naturally aspirated engine.

[jonbill]

FWIW, this is mine. Works well. 'added' mode didn't seem to work for me, so I use 'switched'.

Screenshot 2022-11-22 at 20.50.04.png (966.98 KiB) Viewed 1214 times

[MattSkelton]

Useful @jonbill as at least i know what useful looks like!

[jonbill]

most people find it back to front, assuming a -ve delta needs more advance but actually delta is "target - actual", so a negative delta needs less advance.

[MattSkelton]

Ahh found the WIKI now... going to set up here and then port them into the car tomorrow. I'll do a log on the way to work tomorrow its only about 5 miles so not too long.

[MattSkelton]

most people find it back to front, assuming a -ve delta needs more advance but actually delta is "target - actual", so a negative delta needs less advance.

Is this for the Switched mode as you switch out your advance table?

[jonbill]

I think the meaning of delta is the same with switched and added.

[MattSkelton]

Armed with fresh knowledge i had a fiddle!

Short log here the website doesnt like .mlg files! The tune is uploaded too.

I am still on added but may go switched, it drops a bit but not worrying me as to if it stalls not perfect but better.