Opel fuel trims is Fixed

Wightscope wrote: I note also that about 4 crank revolutions before the event the voltage starts to drop from 14.2v down to 12.24v at the time of the out of turn firing, that could be a clue as it comes first.

It's not just voltage that is dropping. RPM is also getting pulled down. Almost 900 RPM when voltage starts falling on down to under 500 RPM right before the event. Then RPM flares up over 1,300 right after the event. Can also see the injector pulses getting fatter. If this did happen in gear it should've been very noticeable unless the clutch is spanked.....




Also found this after a fuel cut where #4 is the last injector to turn back on. Might be deliberate but there are other fuel cuts where it doesn't happen??

Here is coil cyl 4
www.dropbox.com/s/y732zjhqoo08ufa/Opel_A...Coil%204.psdata?dl=0

coil cyl 2
www.dropbox.com/s/obaaldirpwm3816/Opel_A..._cyl%202.psdata?dl=0

Interested to hear other's take on this but in my interpretation , some firings on 2 and most on 4 indicate excessive turbulence in the cylinder.This can be caused by bad atomisation or valve issues, but AFAIK it's usually caused by excessive EGR. This may tie in with the voltage drop on the injector circuit if the EGR solenoid is randomly open and certainly would cause the slowing. I can understand the ECU not firing the injector if it detects a misfire but not sure how that explains the double injector firing.However, if it was EGR I would expect to see it evenly across the cylinders - though it maybe and it's just that Cyl 4 has the weaker coil - I note that the peak was 400v on your scope earlier but Cyl 4 is showing only 240v Next step for me would be to amp clamp the EGR solenoid supply during an event, also check that the position sensor is making sense as it could be under reading.

Maybe to much waveforms but here is without any faults when driving. I think I am on cyl 4 ignition I am only follow wiring diagram but have no way to sync this when it is an ignition cassette .
www.dropbox.com/s/yiya4ie1cul51wt/3.psdata?dl=0
www.dropbox.com/s/8yi8j5i11yd8t4l/Opel_i...4%20good.psdata?dl=0

Well that all looks good to me.
I'm having scope withdrawal so happy to look at your waveforms!

More Pico files I captured some data under misfire cyl 4 ignition and cam sensor, it is interesting one file big spikes on the cam signal from what I think is ignition could that cause the injector fire in the wrong moment, also when it misfires after restarting no problem strange. Too bad, it is not easy to move probes to injectors but I try tomorrow again scope injectors, I will do a battery test with Pick in the evening we have a snowstorm just now so it is a little difficult.
www.dropbox.com/s/0tl3iha3t67iipb/cam%20...0cyl%204.psdata?dl=0
www.dropbox.com/s/eni28qtgdrfmisu/cam_cyl%204%20ign.psdata?dl=0
www.dropbox.com/s/jyf0ivcxwk3xzur/under%20misfire.psdata?dl=0
www.dropbox.com/s/mduyhb5sc21kdbr/after%...0misfire.psdata?dl=0

Crikey!
Well to state the obvious the primary or secondary voltage is leaking into the 5v ref, this is spiking the cam sensor - at some points off the +/-10v scale so no wonder the ECU is confused as to where it is.
There is also a 300-500mv ripple on the 5v ref at 30-180kHz, which I think is too high to be a solenoid or alternator.
You mentioned the cassette had been replaced - is it genuine and do you have the original. I am wondering if the actual problem was the CKP sensor that you replaced and this is an induced problem.
I notice that the primary spike is dropping from 350 to 250v which indicates a short and the cam sensor voltage spikes as the coil discharges across the plug. You can see when misfiring that the same but much smaller spikes happen in the 5v ref when the other plugs fire. Take a look at the plug in 4 as well, even when not misfiring I can see the spark escaping, maybe swap the plug over.

I don't know the arrangement of the engine but look for anywhere the 5v ref and primary/secondary are in close contact - ECU plug, a 5v wire clipped to the top of the coil pack for example. Is Cyl 4 next to the cam sensor by any chance? Also it maybe 5v to something only switched on at certain times

Under misfire CMP at +/- 10V! looks like it causes an extra firing


No misfire but spark escaping

If you want to check the synch you can stick a coin on top of the cassette over where the coil should be and put your probe on it (with an attenuator just in case) you should pick up the secondary enough for a synch. Don't connect the earth.

Demo :


HOWEVER - as you may have a coil leak I would wrap that coin in some rubber or layers of electrical tape just in case there is a crack in the insulation

I don't know if it is the original coil pack but I doubt it because I guess that is no 1 item when people troubleshoot and repair they change it is easy.
It is an NGK coil pack and the owner bought an NGK coil pack but with the same problem I switched to the old one but I think the new one was never tested after a new crank sensor.
This is a picture of the ground wire to the coil pack the owner of the car or the dealership did this repair it was not a nice one and it did a loop around the other wires you never know if that could interfere with it is a picture before and after repair.

Now the computer shot down the number four injector that's why the problem goes away when restarting the engine, there is no more double firing of the injector driving around for a great amount of time. I also have primary and secondary with ignition probe taken at startup in a warm garage.
www.dropbox.com/s/490g18aed3uzn4s/shotdown.psdata?dl=0
www.dropbox.com/s/y6kavbw2r7x482r/opel%2...0cyl%204.psdata?dl=0

Can't see much from the secondary, but it's the same as the primary anyway.

Pull the pack and take a look for carbon tracking on the plug or inside the boot.
Good idea to switch the pack back now you have fixed the crank sensor, if that does not fix it then maybe switch the plugs around and see if the problem moves.
That spark is going somewhere as you can see by the waveform. The leakage leaks into the 5v ref on the cam, confuses the ECU about where it is in the firing cycle causing the injector to fire twice.
At least that's the theory so far. Fix the spark leakage and you will have fixed it. Probably!

Changed the coil pack and new spark plugs to NGK also bought a used fuel injector and put it on cyl 2 and the cylinder 2 injector on cylinder 4 where the scanner detected the misfire. Also checked the fuel pressure 52 psi at idle and with a snap, it stayed the same.
Fuel trim first before engine warm-up great at idle and showed correction at cruising at 2200 rpm long term 17 short term -15 warm engine longterm 20 and short-term 12 total +30 but is with steady throttle around 2000 rpm if I accelerate the fuel trim is 0 and also at idle. It is only steady throttle 50 mph
MAP sensor is around 2 volts at partial load 200 rpm. 02 sensor working. No code so far or check engine light.
www.dropbox.com/s/6mgtnzll7mo7i0z/fuel%20pressure.mp4?dl=0

If there is no problem at idle, I guess no vacuum leak and no problem giving full throttle it could not be fuel or restricted fuel injector, so it must be an input problem. An EGR fault would provide different symptoms. Also, PCV will give bad idle. TPS sensor? MAP sensor at 2.5 volts around 200 rpm seems ok. This is my thought process. I have an old Audi (1988) with almost the same problem but more noticeable you could feel the car miss easy no fishbite the fuel pump took care of the problem.

Re-scope the cam sensor and see if the signal is now clean. Maybe look at another 5v ref as well.

Have a waveform on TPS I took it with the key on engine off but it barely moved it is also so with the scan tool but driving there is bigger movement in the waveform on the scan tool I wish I had taken a waveform at the sensor with Pico and running. an older car you could check TPS with the engine off but what about this car. Here is also capture with cam sensor and MAP sensor no problem it looks to me.

www.dropbox.com/s/pbkgmppd0is0lac/opel%2...20signal.psdata?dl=0

www.dropbox.com/s/o41b1j4x45e5gb0/opel%2...0map%201.psdata?dl=0

TPS running engine works it seems
www.dropbox.com/s/oo48s65kh5y4fgv/opel%2...running3.psdata?dl=0

Is the problem still present?

Both on the cam signal and the TPS there is a huge amount of noise, the TPS has a solid 3.5v of repeating pattern noise

same problem high fuel trim adding fuel when steady throttle around 2000 rpm. Perhaps there is less noise if I use sensor ground. I am at battery ground

I noticed that there was comment about maf. That engine does not have maf. Its just intake air temp sensor.

And that engine is "famous" from egr causing check engine light and misfires.

Story goes like this: Egr-channels get blocked. Because only map, ecm doesn`t know it. Egr-flow is missing, more air to combustion process than expected -> lean condition(causing missfires).
If bad enough, easy to verify. Remove egr-valve connector and test drive.
Because lean condition, p0170 is usually seen too.

Picture of the channels:
i1011.photobucket.com/albums/af236/smoki..._jpg_zps11a212d4.jpg

Yout need to remove intake manifold, and middle part where injectors are. I recommend cleaning anyway, because if those are not blocked right now, blocage is coming, sooner or later.
2-3 hours of work if you have tools and thumbs in right places.

Yes, the intake manifold is not wasted time anyway nice to take a look into the EGR channels, why I did not take that route right away was because I energized the EGR valve at Idle and the car stalled right away. I try to figure out why the throttle blade does not move with the ignition on when pressing the throttle pedal it seems odd. Then there is the hash on the signal wire also but that might be from using battery ground, next weekend I try to work on the car.