I would recommend that each buyer of B58 receive an unlimited amount of Xanax or similar sedative meds.
You will ask – why?
When I finished the experiments, I put the “correct” ignition coil in the nest of the 2nd cylinder (the ignition coil used for the experiments will not be used for daily driving). Everything should be fine, wouldn’t it? I started the engine. After several seconds, several misfires started, and a second later – one of the cylinders was already turned off. The car started to vibrate, and DME started to dry the spark plugs – the familiar howling started to sound from the engine compartment.
Unfortunately, the situation only got worse. Smoke clouds from the exhaust, a pungent smell. The car vibrates, the engine shivers, and EML blinks.
I connected the ISTA to record this event as much as possible.
In the image, we see:
a. Combustion time of all cylinders is correct (so it is not my error by putting back/connecting the ignition coil);
b. an abnormal number of misfires identified in the 3rd (!) cylinder, then cylinder No.2 follows;
c. third place – cylinder No.4, which also has a large number of misfires.
On the 13th second, the misfires counters are cleared, and the counting starts from the beginning. Now the sequence (starting with the max): 2nd/3rd/4th, the remaining cylinders have problems too!
Complete crash of the engine!
Isn’t that impressive?
The attributes of these many “damaging” error messages are more impressive:
Here, not a word regarding fuel mixture! Not a word regarding LTFT, STFT – ZERO data!
Reasons? Not enough space in the list?
At the same time, there are even 3(!) recordings regarding fuel amount in the fuel tank. One would be enough – fuel amount in the side of the pump.
At the same time, there are FOUR (!) records regarding coolant/engine temperature.
On this background, the recording regarding Ambient pressure seems funny. Maybe Bosch predicts some global abnormalities? Perhaps they had an experience when the mass misfires were caused by completely incorrect fuel pressure? Maybe Bosch gets ready to run these engines in space?
The reason for this crash?
The reason is quite trivial – as Bosch (after the phase of CO catalytic converter warm-up) “dos not see” misfires (if the combustion time stays more or less correct), all LTFT “goes crazy”. More about this problem here.
My humble opinion – DME algorithms in this situation are a complete fail. When seeing significant abnormalities in the amount of consumed air, mechanical efficiency of the engine, and incorrect exhaust gases – what’s the point of (significantly) changing LTFT? Such desperate “adapting” leads to one thing – a harsh engine performance crash after the restart of the engine (if the reason is the misfires of some cylinder and the problem disappears after the restart).
Misfires are the most common problem with petrol engines. Due to misfires of several seconds, the car’s engine reached the stage when the vehicle should be delivered to the service by the evacuator. Very impressive, Bosch!
Solution of the problem? Readaptation of the engine. Of course, the cause of the misfires should be solved – I think there is no dispute regarding it.