Why too rich?
The secret is probably found if I look into the calc model
My stock BMW
I upgraded my summer daily driver from 1.1.70 to 1.1.91 the other day, now that 1.1.91 had been released for a week. I began by first warming up the car and seeing if it ran as it should after winter storage and it showed no sign of problems.
I upgraded to 1.1.91 and started the engine, it ran rough and I immediately adjusted req fuel as I suspected it ran rich by the sound of it. To my surprise I had to lower it to 8-9 ms down from the previous 16.3 that was used with 1.1.70.
Looking for my mistake I warmed up the engine properly after that and downgraded to 1.1.70 and restored the old configuration file, sure enough it ran like clockwork again with req fuel of 16.3 ms.
I can't find where I went wrong, can you help me?
Short engine specification :
- Stock BMW M20B20, 2.0 litre 6 cyl, 2 valve/cyl
- 133 cc/min injectors Req fuel = 6.49*(2000/6/133) = 16.3
- Wasted spark coilpack (originally distributor but has 60-2 trigger)
Log files
- Upgraded to 1.1.91 [Idle with 1.1.91]
- After downgrading to 1.1.70 to check [Idle with 1.1.70]
The V8
I got rushed into a short job on a V8 which didn't start too well due to bad injector and cranking settings with large injectors, 1680 cc/min on 6.2 litre engine with gasoline = bad.
I fixed that and tuned it with the the firmware that was in the ECU at the time which was 1.1.81, after I was nearly done I upgraded to 1.1.91 and started the engine. I did some trimming at low rpm in the VE map and thought nothing of it, with these injectors it's not easy to get a perfect tune but when some load was put on the engine it ran rich.
Log files:
This is why I'm confused, the VE maps look like this with the firmwares with reasonable tuning on 0.6 bar boost :
It's obvious I had to remove a lot of VE to get the tune right.
Here's why, but I'm not sure it explains why I had to halve the req-fuel on the BMW :
