99 PCM replace/update
#226
CF Veteran
I have a Hantek 8 channel. It works.
Interestingly, the crank channel looked pretty good on initial start up but deteriorated within a couple minutes. Might be looking at a pending thermal failure. Also interestingly, when my original sensor failed, I had at least 6 total shutdowns before I ever received a code. Getting to be an OBDII reader is about as obsolete as an 8-track player.
I'll get a Mopar sensor and generate some normal waveforms. Might as well get another AZ sensor since it's free and see how it performs out of the box.
Don't mean to jack your thread but I'm sure 97G is anxious for another chapter to read.
Interestingly, the crank channel looked pretty good on initial start up but deteriorated within a couple minutes. Might be looking at a pending thermal failure. Also interestingly, when my original sensor failed, I had at least 6 total shutdowns before I ever received a code. Getting to be an OBDII reader is about as obsolete as an 8-track player.
I'll get a Mopar sensor and generate some normal waveforms. Might as well get another AZ sensor since it's free and see how it performs out of the box.
Don't mean to jack your thread but I'm sure 97G is anxious for another chapter to read.
#227
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From: CO
Year: 99
Model: Cherokee (XJ)
Engine: 4.0
No sir, your not jacking the thread at all, we are imploring an issue and I appreciate every bit of your contributions. Thank you
After all the threads I've read, sites, forums..... this is the first that you and awg have covered some much needed food for thought, ideas, because not every diagnosis is cut and dry. Please by all means post your newfound wave forms. This is a good collection of knowledge and I find it highly useful.
You humbly say 8 channel, that makes me chuckle as 8 channels and it's capable to say the least. Lol
Awg strongly recommends having a trained doagnostic technician scan my jeep, however with both your knowledge I haven't heard weather you bekieve I can achieve enough information with a 2 channel cheaper scope, or is this a waste of money?
After all the threads I've read, sites, forums..... this is the first that you and awg have covered some much needed food for thought, ideas, because not every diagnosis is cut and dry. Please by all means post your newfound wave forms. This is a good collection of knowledge and I find it highly useful.
You humbly say 8 channel, that makes me chuckle as 8 channels and it's capable to say the least. Lol
Awg strongly recommends having a trained doagnostic technician scan my jeep, however with both your knowledge I haven't heard weather you bekieve I can achieve enough information with a 2 channel cheaper scope, or is this a waste of money?
Last edited by 4x4jeepmanthing; 07-13-2019 at 09:45 PM.
#228
CF Veteran
Awg strongly recommends having a trained doagnostic technician scan my jeep
I haven't heard weather you bekieve I can achieve enough information with a 2 channel cheaper scope, or is this a waste of money?
If you want to get a cheap oscilloscope, get one designed for automotive use so you get a pile of automotive software that does most of the setup work for you and gives you some useful leads.
#229
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Joined: Mar 2016
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Year: 96
Model: Cherokee (XJ)
Engine: 4.0
did you find the learning curve difficult?..(which is why I suggested the OP find a tech, instead of buying a scope and learning himself)
As you have kindly provided that info & snapshot to help him move forward, if I was the OP, I would probably bite the bullet for a Hantek
which if you want to go to "next level" fault finding, you cant really buy a toy, it needs to be a fit for purpose tool
think the full Hantek kit is under $US200 ?
#230
CF Veteran
Did a voltage check on all the injectors, and they're fine. Representative waveform:
Seems pretty clear that CPS is not solely responsible for their activity.
Need to look at timing stability.
Seems pretty clear that CPS is not solely responsible for their activity.
Need to look at timing stability.
#231
CF Veteran
I'll never own another 8 cylinder, so I'm good.
The biggest complaint I've heard about Hantek is getting the software installed. Apparently some people don't know how drivers work.
did you find the learning curve difficult?..(which is why I suggested the OP find a tech, instead of buying a scope and learning himself)
As you have kindly provided that info & snapshot to help him move forward, if I was the OP, I would probably bite the bullet for a Hantek
That said, I'm looking at my CPS and saying "Just WTF is it that you actually DO!?"
which if you want to go to "next level" fault finding, you cant really buy a toy, it needs to be a fit for purpose tool
think the full Hantek kit is under $US200 ?
#232
CF Veteran
97G has his own problems now, but yeah, that CKPS signal looks a bit hosed. Thanks for posting.
#233
CF Veteran
#234
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Joined: Mar 2016
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Year: 96
Model: Cherokee (XJ)
Engine: 4.0
have you read this one I just stumbled across ?
https://www.pirate4x4.com/forum/jeep...-hate-xjs.html
note the picture of the flexplate with slight ding
I do not recall you reporting back on my proposed flexplate examination,
not sure myself how easy it is to do, but being one of very few common parts, there is really no option imo but to exclude this possibility
(though it was not the issue in the case study shown)
https://www.pirate4x4.com/forum/jeep...-hate-xjs.html
note the picture of the flexplate with slight ding
I do not recall you reporting back on my proposed flexplate examination,
not sure myself how easy it is to do, but being one of very few common parts, there is really no option imo but to exclude this possibility
(though it was not the issue in the case study shown)
#236
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18 Posts
From: CO
Year: 99
Model: Cherokee (XJ)
Engine: 4.0
have you read this one I just stumbled across ?
this is a new thread to me, interesting back and forth.
https://www.pirate4x4.com/forum/jeep...-hate-xjs.html
note the picture of the flexplate with slight ding
I do not recall you reporting back on my proposed flexplate examination,
I have not purchased a dial, however I still need to pull the cover and take some photos while rotating the plate.
not sure myself how easy it is to do, but being one of very few common parts, there is really no option imo but to exclude this possibility
(though it was not the issue in the case study shown)
this is a new thread to me, interesting back and forth.
https://www.pirate4x4.com/forum/jeep...-hate-xjs.html
note the picture of the flexplate with slight ding
I do not recall you reporting back on my proposed flexplate examination,
I have not purchased a dial, however I still need to pull the cover and take some photos while rotating the plate.
not sure myself how easy it is to do, but being one of very few common parts, there is really no option imo but to exclude this possibility
(though it was not the issue in the case study shown)
#237
CF Veteran
I'm gonna stop short of saying "Boy you really need to out and buy this!!" tho. It has a few shortcomings (like it's difficult to measure stuff easily, and all those missing spikes were a software or acquisition problem which I need to explore); you have to ask yourself how many times are you actually going to use it so can the cost be justified; and it'll take a bit to get the hang of understanding stuff (I've got a lot of background in waveform analysis so I don't really have a "learning curve"). OTOH, it's cheap, and in the above example it can tell you everything you could possibly need to analyze signals. And I guess a lot of the time you're interested in basically if you got a waveform or not.
#238
CF Veteran
Good stuff.
How do you manage to get those screen shots though, without showing your thumbs or background in the picture?
just curious
How do you manage to get those screen shots though, without showing your thumbs or background in the picture?
just curious
#239
CF Veteran
The Hantek "oscilloscope" is just a signal generator. The software is Windows based. Hantek connects to the laptop via USB. Hit printsceen, edit with Irfanview, post.
Last edited by Dave51; 07-19-2019 at 08:12 PM.
#240
CF Veteran
If you buy a Hantek...
If you look at the specifications of the device:
2.4 mega-samples per second should easily and reliably collect a signal of 200Hz. By my calculations, a CPS running at idle is pulsing at about 225Hz so this thing should have put up a quality waveform of the CPS easily.
Welllllll, there's that little disclaimer there that says "Single Channel". Turns out low end oscilloscopes often utilize a pile of converters to generate a signal. One converter will collect for a bit, then another one will collect while the first processes data, and so on ("interleaving"). If you're only running a single channel you get to use all the converters, but if you add more channels, less converters are available, and if you're trying to collect a very busy channel some things get distorted or are missing altogether ("aliasing").
Testing this on the 1008C, I put up 2 CPS waveforms on a 50ms scale and got
However, the act of simply adding another channel caused aliasing to appear:
There are several ways to correct aliasing, but it appears the only way to do that on the 1008C is by reducing the timescale (NBD)(which is what was done on the initially-posted waveforms)(which is what I should have done before getting a new CPS and changing it out)(which is why I am a big stoopid).
Parts cannon fires again...