99 PCM replace/update
#347
CF Veteran
Joined: Mar 2016
Posts: 3,551
Received 663 Likes
on
566 Posts
Year: 96
Model: Cherokee (XJ)
Engine: 4.0
[QUOTE=4x4jeepmanthing;3583435]everything distributor wise is new now. this happened with mopar distributor assembly and aftermarket.[/QUOTE
sorry, my bad on the timeline, feel bit like a detective interrogating a serial sex offender suspect
I admire your determination, at least you will be good to keep your XJ on the road in future
In addition, if you end up having to change timing chain, it will probably be less time consuming than all this electrical work
sorry, my bad on the timeline, feel bit like a detective interrogating a serial sex offender suspect
I admire your determination, at least you will be good to keep your XJ on the road in future
In addition, if you end up having to change timing chain, it will probably be less time consuming than all this electrical work
#348
CF Veteran
Can you reduce the vertical on the coil? Also, add Measurement, Maximum to each of the channels.
Are you getting a used, or free CPS to try? If not, I'd keep looking for the entry point for that scatter, including isolating the CPS sensor signal back to ECU, and for that matter, all the coil wiring.
Did you replace the coil wire?
When it's pitch black outside take a look around there and see if you can spot any arcing.
Are you getting a used, or free CPS to try? If not, I'd keep looking for the entry point for that scatter, including isolating the CPS sensor signal back to ECU, and for that matter, all the coil wiring.
Did you replace the coil wire?
When it's pitch black outside take a look around there and see if you can spot any arcing.
#349
CF Veteran
NM I see you did that by your answer in the quote above
Change thought process. Rather than thinking it's a CPS problem, consider it a coil problem. If you go back to the first waveforms
you've got coil scatter in the CKS too. If all of the Hantek components are away from the coil (these are inexpensive cables so probably very susceptible to interference) then we should consider the coil leak (short) to ground instead of CPS.
You could try doing additional investigatory experimentation (screwing around) by looking at other sensors (injectors or stuff near the coil) to see if there's artifact there as well.
...and for that matter, all the coil wiring.
you've got coil scatter in the CKS too. If all of the Hantek components are away from the coil (these are inexpensive cables so probably very susceptible to interference) then we should consider the coil leak (short) to ground instead of CPS.
You could try doing additional investigatory experimentation (screwing around) by looking at other sensors (injectors or stuff near the coil) to see if there's artifact there as well.
Last edited by Dave51; 11-26-2019 at 08:01 AM.
#350
CF Veteran
#351
Thread Starter
CF Veteran
Joined: Jun 2016
Posts: 1,011
Likes: 0
Received 20 Likes
on
18 Posts
From: CO
Year: 99
Model: Cherokee (XJ)
Engine: 4.0
now that both sensors are new that spike does have me curious, your graph didnt have any of that, better scope to though.
#352
CF Veteran
or just crappy probes?
your graph didnt have any of that, better scope to though.
now that both sensors are new that spike does have me curious,
#354
CF Veteran
Hey, it's easy and free, so start there.
After that, unbolt the coil and hold it away from any potential grounds, move wires while monitoring the cam waveform to detect any change.
Did you say you have new plug and coil wires?
After that, unbolt the coil and hold it away from any potential grounds, move wires while monitoring the cam waveform to detect any change.
Did you say you have new plug and coil wires?
#356
Thread Starter
CF Veteran
Joined: Jun 2016
Posts: 1,011
Likes: 0
Received 20 Likes
on
18 Posts
From: CO
Year: 99
Model: Cherokee (XJ)
Engine: 4.0
well i tried checking for arc with at testlight and looking in the dark with no luck. Im still curious as to this spike and what could be causing it. when i went through the harness I soldered, tapped, and ohmed everything before replacing it. I have no idea other of what this code be from, the spark plug wires are the only thing that have not been replaced lol, though I did ohm these while moving them around before I choose to use them vs my old ones when I swapped engines.
more importantly ive put a code reader on the jeep and p1391 is no longer being registered!!!!! looks like I can put my CEL light back in the dash.
more importantly ive put a code reader on the jeep and p1391 is no longer being registered!!!!! looks like I can put my CEL light back in the dash.
#357
CF Veteran
Joined: Mar 2016
Posts: 3,551
Received 663 Likes
on
566 Posts
Year: 96
Model: Cherokee (XJ)
Engine: 4.0
and the probes being stuck in has "forced" a better contact, just something to bear in mind if it does return
I had this happen to me and was fortunate to find it was the female pin in a connector had been forced back a wee bit
Last edited by awg; 11-27-2019 at 08:28 PM.
#358
CF Veteran
This thread is #10 all-time on the list of Normal Threads in terms of replies!
My morning news thread!
Things just won't be the same...
My morning news thread!
Things just won't be the same...
#359
Thread Starter
CF Veteran
Joined: Jun 2016
Posts: 1,011
Likes: 0
Received 20 Likes
on
18 Posts
From: CO
Year: 99
Model: Cherokee (XJ)
Engine: 4.0
Yes yes, the lack luster diagnostic merry go round is over, I hope, but hey, I haven't tried kerosene yet so there's that.
I do appreciate all of your patience and guidance walking me through some of these diagnostic ideas, it has been a great learning opportunity, and there has been tons of helpful ideas that I'de never read of on related threads. For what it's worth I still spent less on the scope and sensor, even though we still have a weird spike in the signal, then what I would have for a shop+ parts.
thank you
I do appreciate all of your patience and guidance walking me through some of these diagnostic ideas, it has been a great learning opportunity, and there has been tons of helpful ideas that I'de never read of on related threads. For what it's worth I still spent less on the scope and sensor, even though we still have a weird spike in the signal, then what I would have for a shop+ parts.
thank you
Last edited by 4x4jeepmanthing; 11-28-2019 at 08:58 AM.
The following users liked this post:
Dave51 (02-29-2020)
#360
CF Veteran
Right. The xj AW4 has one. The zj 42RE does not. My bad. 3 years late on the apology but better late than never?
Thread
Thread Starter
Forum
Replies
Last Post
DELTA3
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
19
06-26-2024 08:26 AM
sushil@zayani.com
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
0
01-02-2018 11:04 AM
Turbo Supra
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
26
07-04-2017 04:28 PM
rwhealey
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
0
12-11-2015 07:03 PM
gottarollwithit
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
1
11-25-2012 06:26 AM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)