Switching two cylinder running

Ask for and share advice on using the PicoScope kit to fix vehicles here.

Re: Switching two cylinder running

Postby volrem » Wed Mar 02, 2016 7:22 am

Hi

That last file is OK and shows good piezo injector current. Lower part is being cut off because probe settings. You should create custom probe for your clamp to get it display -10 to +10A. Currently its -5 to +10A

Now add cam crank and two injector currents in the same waveform.

I had a quick look and it seems that cam signal is correct and not inverted.
volrem
Guru
Guru
 
Posts: 146
Joined: Fri Jan 03, 2014 3:43 pm
Location: Estonia

Re: Switching two cylinder running

Postby Terry Ferguson » Wed Mar 02, 2016 10:21 am

Thanks for that, Glad somethings OK, I thought it looked like a good signal, I will set up 2 Clamps on the injectors, Cam & Crank on the settings yyou sugest, I know I can pick 2 injector wires that have that same Good patern, But the other two have a lot more Interfearence, Wavy line Ossilations, But there is a Faint 3 event signal, just!, nothing as clear as the one I posted. Would you have any idea Why 2 cylinders would go off & show this different signal? Then the next time I start it, the two that were off are now back running & showing that same good waveform, The previousle Running cykinders are now off with Bad wave form? This is why I sent the ECU for test, But some thing is obviousley giving it, the wrong info to act on, Your help is very much appriciated, I'll do the scope & post the Waveforms, Thanks Terry
Terry Ferguson
User
User
 
Posts: 33
Joined: Wed Feb 24, 2016 7:03 pm

Re: Switching two cylinder running

Postby Terry Ferguson » Wed Mar 02, 2016 9:09 pm

Hi I got the Smax wired on the scope today (still running on 2 cylinders now on 1 & 4) I have Chan A: Break out lead to Crank sensor, B: has Back probe to Cam Sensor, C: & D: Have 20 amp clamp on injectors 1 & 4, I thought I would capture a Running & non Running Cylinder, But when I started it, it was Running on 1 & 4, This is shown in the first file, I then swapped 1 "20 amp Probe" to a non running Cylinder, I'm sorry I was advised to set a custom probe at -10 to + 10 , But it appears I have made a mistake with this, I did not have the time to sort out how to set up the custom probe today, I am working on this & found it in Tools, So I'll try for next time, I have put a file showing Cam & Crank, Then another with 2 injectors, The Cam & Crank Looks the correct pattern , it is the same as the Smax sample in the waveform Library, But I have to say I don't Know what it means, If some one can explain What the Gaps in the crank sensor Waves represent? are they (TDC), Also on the Cam pattern where dose this relate to TDC compared to the Crank, Then where do the injectors fit in? I would expect the injection event should be some where near TDC , But on this pattern there seems to be no relation, I would value some interpretation, I thought there would be a TDC event on a couple of sensors to coincide at some point?? Crank & Cam must relate? Thanks Terry
Attachments
Ford_S-Max_2007_Diesel cam crank 2 injectors.psdata
This is CAM Crank & 2 Injectors
(17.62 MiB) Downloaded 38 times
Terry Ferguson
User
User
 
Posts: 33
Joined: Wed Feb 24, 2016 7:03 pm

Re: Switching two cylinder running

Postby Terry Ferguson » Wed Mar 02, 2016 9:21 pm

Hi I got the Smax wired on the scope today (still running on 2 cylinders now on 1 & 4) I have Chan A: Break out lead to Crank sensor, B: has Back probe to Cam Sensor, C: & D: Have 20 amp clamp on injectors 1 & 4, I thought I would capture a Running & non Running Cylinder, But when I started it, it was Running on 1 & 4, This is shown in the first file, I then swapped 1 "20 amp Probe" to a non running Cylinder, I'm sorry I was advised to set a custom probe at -10 to + 10 , But it appears I have made a mistake with this, I did not have the time to sort out how to set up the custom probe today, I am working on this & found it in Tools, So I'll try for next time, I have put a file showing Cam & Crank, Then another with 2 injectors, The Cam & Crank Looks the correct pattern , it is the same as the Smax sample in the waveform Library, But I have to say I don't Know what it means, If some one can explain What the Gaps in the crank sensor Waves represent? are they (TDC), Also on the Cam pattern where dose this relate to TDC compared to the Crank, Then where do the injectors fit in? I would expect the injection event should be some where near TDC , But on this pattern there seems to be no relation, I would value some interpretation, I thought there would be a TDC event on a couple of sensors to coincide at some point?? Crank & Cam must relate? Thanks Terry
Attachments
1 Running injector on A dead on B.psdata
(3.27 MiB) Downloaded 26 times
Terry Ferguson
User
User
 
Posts: 33
Joined: Wed Feb 24, 2016 7:03 pm

Re: Switching two cylinder running

Postby Terry Ferguson » Wed Mar 02, 2016 9:42 pm

Hi I got the Smax wired on the scope today (still running on 2 cylinders now on 1 & 4) I have Chan A: Break out lead to Crank sensor, B: has Back probe to Cam Sensor, C: & D: Have 20 amp clamp on injectors 1 & 4, I thought I would capture a Running & non Running Cylinder, But when I started it, it was Running on 1 & 4, This is shown in the first file, I then swapped 1 "20 amp Probe" to a non running Cylinder, I'm sorry I was advised to set a custom probe at -10 to + 10 , But it appears I have made a mistake with this, I did not have the time to sort out how to set up the custom probe today, I am working on this & found it in Tools, So I'll try for next time, I have put a file showing Cam & Crank, Then another with 2 injectors, The Cam & Crank Looks the correct pattern , it is the same as the Smax sample in the waveform Library, But I have to say I don't Know what it means, If some one can explain What the Gaps in the crank sensor Waves represent? are they (TDC), Also on the Cam pattern where dose this relate to TDC compared to the Crank, Then where do the injectors fit in? I would expect the injection event should be some where near TDC , But on this pattern there seems to be no relation, I would value some interpretation, I thought there would be a TDC event on a couple of sensors to coincide at some point?? Crank & Cam must relate? Thanks Terry
Terry Ferguson
User
User
 
Posts: 33
Joined: Wed Feb 24, 2016 7:03 pm

Re: Switching two cylinder running

Postby volrem » Thu Mar 03, 2016 3:54 pm

Your cam and crank correlation is 3 degrees off compared to know good from wavefrom library so it should be good.

Second file has too small timebase. You have 2ms/div (20 ms/div) but at 900 rpm idle there is about 34ms between two cylinder injection events. So even if there was something then it's off the screen.

More time is better. Remember you can always zoom in.
volrem
Guru
Guru
 
Posts: 146
Joined: Fri Jan 03, 2014 3:43 pm
Location: Estonia

Re: Switching two cylinder running

Postby Terry Ferguson » Thu Mar 03, 2016 7:31 pm

yes sorry about the 2/ms time base, when I set that scope up I did not really have time, so next will be better, to the cam & crank with 2 injectors, do you think the cam & crank could be out of sync ? can you tell me where tdc is on the crank paten & where it is on the cam sensor paten? I measured both & two of the blus crank are the same as the cam interval, I could do with knowing where tdc is, they look out of sync to me, I would have expected them to be in line at some point? terry
Terry Ferguson
User
User
 
Posts: 33
Joined: Wed Feb 24, 2016 7:03 pm

Re: Switching two cylinder running

Postby volrem » Thu Mar 03, 2016 8:23 pm

Hi


I don't know where TDC is and it doesn't matter at the moment. When you compare measured sync with known good one then you know if it is OK or not.

There was 3 crank degree difference between this and reference. I don't have that reference file at the moment to make an example but maybe tomorrow.

I would like to see cam + crank + injector 1 + injector 2 with 2s/div or 5s/div timebase and sample rate maxed out.
Then make a capture so that whole event from cranking to enough idle is on the same screen. This way it's possible to see if one pair of injectors are being cut off or wont fire at all.
volrem
Guru
Guru
 
Posts: 146
Joined: Fri Jan 03, 2014 3:43 pm
Location: Estonia

Re: Switching two cylinder running

Postby Terry Ferguson » Thu Mar 03, 2016 8:36 pm

When I can get back to it I will set that up, Just to confirm, You want it set at 5 second or 2 second per division, Car not running, then press "Capture" then Start car & Idle for 1 capture, What is the highest capture rate I can set?
Terry Ferguson
User
User
 
Posts: 33
Joined: Wed Feb 24, 2016 7:03 pm

Re: Switching two cylinder running

Postby volrem » Thu Mar 03, 2016 8:43 pm

Terry Ferguson wrote:When I can get back to it I will set that up, Just to confirm, You want it set at 5 second or 2 second per division, Car not running, then press "Capture" then Start car & Idle for 1 capture, What is the highest capture rate I can set?


Well 2s/div gives you total capture time of 20 seconds and that should be enough. But when you start the capture and go to crank and idle with only 5 seconds useful data on the screen then you should use 5s/div. Try it out what works for you to get at crank and and least 10 seconds idle in the screen.

Look at sample interval in properties and try get it at 1microsecond. You have to almost max out sample interval for that and when using 5s/div you probably get only 2microsecond but it should be enough. Just try it out.
volrem
Guru
Guru
 
Posts: 146
Joined: Fri Jan 03, 2014 3:43 pm
Location: Estonia

PreviousNext

Return to Diagnostic discussion

Who is online

Users browsing this forum: No registered users and 0 guests