So i am chasing a CKP fault on a DT466e (egr motor), I know the checks per Navistar fault 147 are all in spec. I put the scope on it and I haven't been able to find a good wave and i don't have another to compare it too. Can someone led a second set of eyes? Sorry still learning with the scopes.I have the file uploaded to google drive as it states to big to load into email or anywhere.
Thank you for posting and please, there is no need to apologise. We all had to start somewhere and the great thing about scope diagnosis is we never stop learning.
If you have the file uploaded to google drive and you don't mind sharing the link here, then it might be easier to drop the link into this post. If not, a picture as muttnjeff suggested will help us understand your settings and hopefully guide you to getting a better capture.
To help you get started and make sure you have something on screen it might be useful to follow the startup settings I've suggested here - viewtopic.php?p=100735#p100735. You can also download the file at the bottom of the post, which you can open in PS6 or PS7 and it will set the scope for you to the settings described.
If you have a particular long capture you can trim this down to just one buffer or select a range. When you click Save As you'll notice another option to select All - Current - Select Range (or Waveform Numbers in PS6). This will help keep the file size down and you should see an approximate file size underneath these settings.
I hope this helps and look forward to seeing your capture.
Hi,
Looking at your waveform and applying a maths channel it would seem there may be an issue with the crank signal. The maths channel appears to show crank speed increasing/decreasing at incorrect times.
I am certainly not the most qualified person to offer you advice and I am sure someone will help you
far more than I, but I saw that in the capture and thought it odd.
As Carl has mentioned there is something with the crankshaft signal when you apply a math channel to display the crankshaft speed. There is possible two things going on here. The first is we have a definite slowing down of the crankshaft as indicated here -
As well as this we also have the issue that Carl has pointed out. Some of this could be down to the math but it is fairly consistent throughout the whole capture and when there are repeating events it's something we should not look over. The only thing that can change this pattern is the crankshaft sensor and the pick up ring which is an area we need to focus on.
As a general rule, if you are looking to use math on these types of signals it is worth remembering to increase the sample rate. You've currently got 1MS which is great and will work absolutely fine with the majority of your captures. If math is needed then increase the sample rate to say 5MS. The more dots on the screen the better the math can function. The trade off though is a reduced number of buffers. It's all a learning curve mxx20 but remember you're not alone.
What I do think we need to take a look at though is the amplitude of the camshaft signal. It is exceptionally low in my opinion. Is there anyway you could get a known good waveform from another machine just to verify? I have read that the cam sensors on these engines are very fussy and if not correctly installed will prevent the engine from starting. If the sensor is too far from the pick up then the amplitude will not large enough and the engine ECU may assume that it isn't turning over. There is a DT466 capture in the waveform library but I'm not sure if the year is correct so it might not be the same. The capture was taken with the engine running which would mean the amplitude of an inductive sensor is higher but you can also see take a look at the differences in timing between the CAM and the CRANK signal.
I hope this helps and please keep us updated with what you find.
Thanks Carl and Ben. I know i bore scoped the crank sensor and the tone wheel has some marks on it(The unit had been at another shop before here and they replaced the ring gear, starter and put a new crank sensor in it, fear is they drove it in and chewed it off, but i cant confirm any of this without removing the trans and flywheel). The cam sensor on this one is a 2 wire and they are almost a set and forget and don't have shims, the pre EGR engines had a halls effect sensor and had to be shimmed and were horribly finicky with shims or end play. I am trying to hunt another EGR DT 04-early 07 motors to see if i can get a known good running one but i haven't had any luck yet.