rusefi.com

NOTE: "fully sequential" gets touted as some holy glorious ideal of EFI, but it's not really required. You'll get better idle emissions and slightly better fuel economy, but at high load/rpm, you're not going to notice a difference. The only potential real difference is that since you know only when a pair of cylinders is firing, you have to fire the ignition system twice as often (hence "wasted" spark), so that can put more heat in to the coils.

plus having a camshaft position sensor probably gives you more opportunities for misfire detection (i.e. it allows you to detect which exactly cylinder is in trouble, which becomes quite handy for V engines)

puff wrote: ↑

Thu Mar 11, 2021 8:45 pm

plus having a camshaft position sensor probably gives you more opportunities for misfire detection (i.e. it allows you to detect which exactly cylinder is in trouble, which becomes quite handy for V engines)

once you're synced you don't actually need to look at the cam sensor any more - the relative phasing between the cams and crank (modulo VVT, of course) is fixed until the timing belt/chain breaks

edit: a big part of the reason for the popularity of the 60-2 crank trigger pattern is that it provides lots of resolution for misfire detection

That all makes sense. I haven't had a look yet, but is there anything in RusEFI for misfire detection yet? Out of curiosity, what actions would a factory ECU take when detecting misfire, aside from turning on an engine check light? Would it try to alter timing or fuelling to compensate in some way?

Some factory ecus disable injection in those cylinders, which also makes sense.

Some engines will also try and tune the per-cylinder fueling and ignition timing to improve smoothness. We don't do anything to detect misfire yet.

Stock VWAG Ignition COP has Ion-Sense .."inside" ..
.. and then ECU can detect misfire ...

I have one Wasted Spark Module for PSA 1.2-1.6 8V engines, and it has one Ion-Sense output also ...

which model is that COP?
what's the benefit of ion sense-based misfire detection on wasted spark modules?
i reckon, misfire detection feature is especially handy for V8 engines since it allows you to identify exactly the head which needs your attention, hence, eliminating the need to remove both heads.

955 602 101 05 - 07C905715A - VR6 3.2
0 986 221 054 - 077 905 115 - V8 (Red one)

Basically, all 4pin COPs .....

what's the benefit of ion sense-based misfire detection on wasted spark modules?
i reckon, misfire detection feature is especially handy for V8 engines since it allows you to identify exactly the head which needs your attention, hence, eliminating the need to remove both heads.

Try to ask yourself, when the misfire is occur..?? (conditions)

It is relatively simple to detect poor combustion in one cylinder from the instantaneous speed of the crank shaft.
A misfire shows up as a period of declining speed at a time you would be expecting a positive speed delta. I.e. the instantaneous tooth time increases at a point you would expect it to decline.

This is how a lot of 90s and early 2000s cars dealt with it.

We do not do this yet but may be able to without much additional work.

it is the "next / higher level" .. of ECU features
1st is Drive engine
....
Xth Failure detection

Minor update - haven't been looking at injection or ignition lately as I've been down to the lower level mechanics, but currently reassembling engine after the rebuild:

Gradually coming together.

JRD McLAREN wrote: ↑

Sat Mar 13, 2021 10:14 am

Stock VWAG Ignition COP has Ion-Sense .."inside" ..
.. and then ECU can detect misfire ...

I have one Wasted Spark Module for PSA 1.2-1.6 8V engines, and it has one Ion-Sense output also ...

I don't think these have ion sensing. Do you have any documentation that says they have ion sense capability?

which one you mean.. PSA ..?? or VW ..??

..one shielded green wire on this Valeo 245097 module is for misfire detection ..
(it is a "dumb" wasted spark coil - PSA)

With the Bosch ECUs there is sometimes "misfire detection" which is only a basic check that a pulse is created on the secondary side of the ignition coil.
BMW used this on most of the COP cars from ~92 onwards, it is useful for detecting a coil failure or a problem with firing the plug but it is not really Ion sensing.

If you test the coils you will probably find a near infinite resistance on the secondary coil (from the ouput pin to the misfire detection pin) which would make them no good for ion.

Any updates?