Switching two cylinder running

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Terry Ferguson
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Switching two cylinder running

Post by Terry Ferguson »

I am new to my Picoscope, I have the advanced 4 channel set, My first case in which to use it is a very strange one, I got a 09 Ford S Max, 1.8 tdci, I was told engine was Scrap & car needed new engine, once in workshop, it did sound Knocking & rough & Smokey, I pulled off the injector wires on each cylinder (to see if Knocking Changed) it was off on 3 & 4, both unplugged made know difference, running on 1 & 2. I done injector leak off test, Preasure test & cylinder Compression test, While doing compresion test I connected Injectors out of Cylinders & they were injecting, All seemed good, when I started car again it was running just the same, But now it was running on 3 & 4, It was now off on 1 & 2, after doing various tests, It ended up running on every combination of Two cylinders (2 & 4, 2 & 3 etc). I removed ECU, which is in the most rediculous place, (passenger Front wheel arch 8 inch off the road at the front) & I hope is the fault, I tested injector wires, Injector to ECU & all wires to ground, all seem fine, I have now sent ecu off for testing, Has any one came across this Switching of Cylinders Firing?? I did put 2 60 amp clamps over the injector wires, the running ones appear (To me) to show a 3 fire event in 5/ms, the ones that were off showed a wavy line patten, with a slight 3 event Just visable, Any help is apppriciated, Also over the period of a week, It has never ran on 4 or even 3 cylinders, always two. Terry
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Fat Freddy
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Re: Switching two cylinder running

Post by Fat Freddy »

Hi

I would think the engine light would be on for this fault. Any codes?

Also it's always best to post an image created using the pico program it's self along side the psdata file (just to see if your set up may be improved).

Personally I don't know this engine but
the running ones appear (To me) to show a 3 fire event in 5/ms
Not sure what you mean here? Also second image is confusing but data file would clear that up and using the Amp clamp would probably be beneficial.

How did you sync to #1?

Also you have four channels. Try adding Cam and Crank also.

Let us know how you go and get back

Cheers
FF

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FioranoCars
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Re: Switching two cylinder running

Post by FioranoCars »

Pico have been very clever and added a screen shot option to the menu, under Edit you have 3 options, the "copy entire window as image" (Alt-E, W) sadly they made the Ctrl-C combo clip just the window, and for most purposes of support the Entire window, not just the graph is essential (channel settings etc).

... Hey Pico, any reason you defaulted the Ctrl-C to just the waveform not full screen? Anyone else prefer the Full screen as default?

It's easy to re-assign, via Tools, Preferences, then see screen shot below:
Re-assign shortcut
Re-assign shortcut
I use a utility called GreenShot (free, just google it) and it has a handy little editor for adding arrows (can change ends to flat not pointy which is useful), and sequential numbered bullets, cropping, torn edge effects, obfuscating etc ... it can screen grab or import he clipboard. Makes tarting things up easy.

As I think I said before, and FF said too, the raw file is essential to really understand the data

Without doubt if you are unsure of your readings and are new to the kit, then try it on a good car and get familiar with a known good setup ... confidence is 80% of using a scope (IMHO) !

Be good to hear how it progresses!
Best
Richard

Terry Ferguson
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Re: Switching two cylinder running

Post by Terry Ferguson »

Thanks for comment, This was the first time I used scope,(so not at recording stage yet) I had it set 10ms/div, X1, 1ms sample rate, trigger Auto. I had two 60amp clamps in 20 amp mode, Clipped over injector wire at ecu. First picture had 1 clamp on a firing cylinder & 1 on a non firing cylinder, I then had It on two firing cylinders, which show 2 identical trace which had what I assume was 3 firing events, these were over about 5ms from first to last, while watching the two firing signs One just went Off as I watched, no miss on the engine, when I moved the clamp to another cylinder wire, it had started running on a different cylinder, I am sorry for my vague description but I am not sure what I am doing with the scope, I am studying as I go, not ready to use scope professionally, but I have it here & thought I would give it a go. Yesterday I had it on a Citroen c3 on the 2 oxygen sensors, I got the pattern I expected for pre cat, But the post cat had virtually the same paten, I'm assuming its the cat at fault from this data & that neither of the sensors are faulty, I also ran graph on delphie scan tool both graphs were 0.1 to 0.8 volts, just double checked I was using pico correctly?

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Fat Freddy
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Re: Switching two cylinder running

Post by Fat Freddy »

Terry Ferguson wrote:Thanks for comment, This was the first time I used scope,(so not at recording stage yet) I had it set 10ms/div, X1, 1ms sample rate, trigger Auto. I had two 60amp clamps in 20 amp mode, Clipped over injector wire at ecu. First picture had 1 clamp on a firing cylinder & 1 on a non firing cylinder, I then had It on two firing cylinders, which show 2 identical trace which had what I assume was 3 firing events, these were over about 5ms from first to last, while watching the two firing signs One just went Off as I watched, no miss on the engine, when I moved the clamp to another cylinder wire, it had started running on a different cylinder, I am sorry for my vague description but I am not sure what I am doing with the scope, I am studying as I go, not ready to use scope professionally, but I have it here & thought I would give it a go. Yesterday I had it on a Citroen c3 on the 2 oxygen sensors, I got the pattern I expected for pre cat, But the post cat had virtually the same paten, I'm assuming its the cat at fault from this data & that neither of the sensors are faulty, I also ran graph on delphie scan tool both graphs were 0.1 to 0.8 volts, just double checked I was using pico correctly?
Whoops :oops: . I wasn't sure you had the clamp. The trouble with camera shots and no files. Too easy to make stuff ups.

Regarding the
3 fire event in 5/ms
I'm inclined to say (without those files and not knowing the engine) that's possibly pre/main injection events. https://www.picoauto.com/library/automo ... celeration

Regarding image two. I suspect you are possibly clamping the same injector. The power supply to (this is where a wiring diagram or previous experience is a must) possibly multiple injectors and the ground wire for that particular injector (which is why you saw it disappear).

As a beginner I strongly suggest a bit of reading. James Dillion's book (can't remember the name) is a basic book to kick off with. Also play around with the demo - easy to learn about how to save files etc.
Also try and get off the habit of auto set up's as soon as possible. The result will be a guaranteed bad capture and frustration.
Reading case studies is a great way of learning how to get a good set up and also an insight on how a system works. https://www.picoauto.com/library/case-studies


Let us know how it goes.

HTH
FF

Terry Ferguson
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Re: Switching two cylinder running

Post by Terry Ferguson »

Thanks for your help, I will as you say do more study on the operation of the scope, to the clamp fitting, I had tested the loom from injectors to ecu, For continuity & Each one to ground, these wires have tested fine, So the clamps were on different injectors, the 3 event signal was only on the 2 firing injectors, I had it on 2 firing & when I looked back one injector had gone down & gave the wavy pattern, When I moved clamp to a previously non firing injector, It was back firing & showing the same 3 event signal, I have now got ecu away for test, I would not be surprised if it comes back & car is the same, If it is, I will try & do the images as a capture & up load it, Thanks again Terry

Terry Ferguson
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Re: Switching two cylinder running

Post by Terry Ferguson »

Hi There, Looking for help, I have now got a different Tested ECU on Trial (its Going back as Fault is Exactly the same) Fitted it & yes the fault is Exactly the same (so Not ECU), Starts & runs Knocking, Off on 2 cylinders I have tried to get pico results, I have to say I am not getting the patens I expected, I will try & post the Saved waveforms, Any info on my settings & results is welcome. I am on a trial with Autovista Diagnostics, Their first test for injectors, is to check ohms across the 2 injector pins & should be 0.25 to 1.5, On all my injectors I have No ohms on any, I have 3 other injectors from a running car & they are the same? Is autovista wrong, They are siemens None coded, Also on the Pico Automotive Scope menu, As I go on Injector test, Diesel, It gives me various choices of injector to test, But no Siemens, They mostly seem to be Bosche, can any one help with speck on these? In the first waveform, It looks like I have a Compression problem & an injecting problem, I have put the 600 amp clamp on A & back pined the number 1 Injector feed With all injectors unplugged, I could be wrong, But it looks to me like it is not firing at a consistent time & has fired twice Close together, Some compression's look to be missing, Although It runs Fine on all the Cylinders at some time, Just not at once, 2 at a time only, I also tried to check the cam sensor wave pattern, again I did not get what I expected, I will put this wave form on & if anyone can advise me I will be grateful, Terry
Attachments
x5 cam sensor wave 2.psdata
Cam Sensor
(15.18 KiB) Downloaded 466 times
crank & inj1.psdata
(16.55 KiB) Downloaded 500 times

volrem
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Re: Switching two cylinder running

Post by volrem »

Hi

Your cam signal looks goot but I don't see any point of it at the moment. Measure at least cam and crank together. Altough signal looks fine I think it may be inverted because of faulty sensor. Measure cam and crank together and compare to known good.

Second file has no diagnostic because sample interval is toooooo high and important information is missing(3,92 ms). First file has 61,1μs and this is also too high.

Crank up your sample rate:
1. Click View
2. Click View Properties
3. Properties tab will open up
4. Adjust sample rate to be 1μs or less.
terry.png
It seems that you have Siemens piezo injectors and these are not controlled like regular injectors.
And you need to measure voltage on both PIN-s and current also. BUT if you have curret OK then there is no need for voltage measurement.

But to check several injectors at the same time you need more than one low current clamps.

Example waveform from siemens system.

I have seen quite a lot people unplugging piezo injector connectors when engine is running but I would recommend not doing that. If you are "lucky" then injector may be left open and then engine damage is for sure. That's because piezo injectors need current for opening and closing unlike solenoid injectors that close when current is cut.
Attachments
terry2.png

Terry Ferguson
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Re: Switching two cylinder running

Post by Terry Ferguson »

I have 2 low amp clamps, I'll take your advise & give it a go, I have a break out lead for crank & will try Cam & Crank, I also thought the cam wave form was inverted But was connected ok (I think) Again I'll check again tomorrow. I have had the low amp clamps on the Loom at ECU & got the first pictures (Camera) in this discussion, I will put the one I got today in File form, Please look at this it is Low amp in 20 amp mode, As you said with my sample rate earlier, Could it be I picked auto settings For Virtual compression test, Then added Injector later on 20v, But sampling would be set for Crank test, Maybe? Are these Pizo injectors They are down as Siemens Common rail , I thought Pizo were Coded, But don't know for sure?
Attachments
cyl 1 running.psdata
This was running cylinder with 20 amp clamp on Loom at ECU
(244.15 KiB) Downloaded 555 times

Terry Ferguson
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Re: Switching two cylinder running

Post by Terry Ferguson »

thanks for Siemens Injector wave forms, The one I have posted, looks Very like the bottom Green on their demo, that was one running cylinder, So this makes me think Mine is ok, But I did have clamp on a cylinder that was not running & had a different pattern, But then Switched on its own to a good firing paten & started running on that cylinder?? This is what led me to get the ECU Tested? I will get a waveform tomorrow of a Good Cylinder & A bad one side by side, with 2 X 20 amp clamps At ecu. thanks terry

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