BTW JMT how you making out? Anything new?

 

BTW2 if you do a sort based on number of replies, this thread is on page 1!

And still never found the answer?

It's been fun tho!

 

This merrygoround has to have an end certainly at some point, the whole idea was to not part canon the jeep.

.So far we know sensors are reporting to the PCM- so says my testing and this "diagnostic" the shop did, not to confident here anymore, I believe 97grand4.0 smelled some thing fishy early on.

. I want to pull the harness and gut the shething for a more in depth look at any breaking or chafing. I also want to replace grounds with nice new copper ring terminals.

. Timing chain wasn't measured, we didn't get that info until I had the pan back on, but it's still a possibility I guess, my 99 motor has the same play if not more on its chain, though the chains are different.

. Might pull the trigger on a new ckp if for No other reason than I should have a backup anyway. I have not shimmed this nor clearanced the current one yet.

I'll get some pictures of the flex plate shutters shortly,



The only other option I seem to have is finding an illusive diagnostics technician that knows how to actually use a scope, or have I missed something?

 

Well I didn't fix it, but Some thing odd happened.

I disconnected the battery negative and unplugged the entire ignition harness. I then stripped all shething and tape from the high bend areas to make sure again that no breakage was missed. To my delight everything looks great on any area I suspected a problem, bends, rubbing areas, all good.

I retapped everything and added gorilla tape on any friction points, plus zip tied the harness up a little higher than it sits stock.

Of course I restarted the jeep after double checking all connections, it starts with out flaw like usual, so I shut it down.

Went inside got stuff together to meet up with family, started it up and No CEL. This hasn't happened ever. Every 2nd start always produces CEL. Anyhow I drive 30 minutes and No CEL. Park the jeep all day, hop in start to drive home and it starts great like usual and still no CEL. This is the 3rd start. I get to the higway and goose it a bit and the flipping CEL fires on.


Any thoughts?

 

And you scanned for codes that the CEL was indicating, and it said.......?

 

P1391

 

Break down and buy a crank and cam sensor, or buy the cranks sensor and go to the boneyard for a cam sensor. But don't put both in at the same time. See if one fixes it. Deja Vous all over again.

 

If you get the scope, you can find out three things:

1. Cam sensor working
2. Crank sensor working
3. Synced

I shoved the crank signal up so you can see how each group of crank signals will stay within a cam block.

 

Just curious, is this your DD? How long can you afford to keep it off the road? How long has it been off the road?

And Dave51, how long have you had yours hooked up to the scope ?

 

Oh, about 10 minutes or so.

 

My cat just alerted me to a snake in my bedroom. So much for window a/c units

 

Hahaha

It's a DD and my only wheels. I haven't had it down, I'm driving it as other than this light nothing is wrong. It drives fine.

 

I found an image of CPS/CKS out of phase



in

https://www.jeepforum.com/forum/f19/...e-fix-3487474/

That poster's oscilloscope is 2 channel and is about $115 with shipping and tax.

However, in the first post you noted

so continuing on this route would require that we conclude your diagnostic guy is an LSOS.

 

Not sure how you can conclude the poster's signals are out of sinc, when it says NO TRIGGER on the side setup. If it was triggered by channel 1 or channel 2 it would likely show in sync?

 

I'm sorry, I'm not understanding your question, but since that poster's waveforms are constantly out of sync (and as mine are constantly in sync) there's no reason to use triggers. Or alternatively, any parameter that you set would be triggered at every pulse.

Which trigger did you have in mind?