I mean, you could have this, too:



https://www.jeepforum.com/forum/f13/...ptoms-1405626/

The center could spin in worse case scenario.

 

I wish I had a better picture of the chain, I tried documenting everything with this.

 

I'm happy to check, but what needs to be done for this, there is no play in the sensor bolts or bell mounts?

 

Pull the inspection plate on the bell housing and check the condition of the flexplate. Has the P1391 been there since you had everything apart?

 

It started before and exists still. I just had the flex plate off to recheck torque converter bolts, I'll pop it off again anyway and see what can be seen.

 

So the 1391 was happening with your old engine?

 

Correct, and new

 

Allright. I see this is about xj, not zj. ZJ did not have the tcm, as the zj and xj have completely different transmissions. My bad.

 

No sweat,


pulled the pan, front had oil seeping, ugh I detest rework. How much play in a chain is normal, it has some, but nothing crazy I don't think. Bought rosin flux for making the test leads as AWG suggested. Do you think a t pin will except solder?

Didn't get around to pulling the distributor cap and checking the chain degree, it was late and I'm beat tired.

 

"If the timing chain deflects more than 12.7 mm (1/2 inch) replace it."

 

you dont really need solder, just a good twist of wire (why thin 5amp is good) and tape it for insulation..doesnt have to be fancy, this is temp test lead

use small safety pins about 1"long

I would really want to eliminate excessive chain slack..that is what the warning code is saying..or an intermitent loss of signal

hopefully ur close

 

Listen closely and you can hear the Pilsbury Dough Boy laughing lol.

 

Lol,


I tried the donor pcm, that didn't work so I called the shop back that did the diagnostic, they are going to give me my money back. Really nice folks, but he didn't even know where to point me because of how well everything looked. They use a Snap on scope. He was happy to take another look, but he also said he believed he wouldn't find anything new if they did. He would like to know if I figure it out.

Anyhow, 7 degree on the chain. I did this twice to be sure. I need to verify that tolerance.

 

I wouldnt accept his money back, but thank him for his time so far...

7 degrees, did you say earlier that was right on the max ?...is that 7* of slack ?

I dont have much experience with chains wearing & stretching, but it does happen on engines with high mileage, set a code on models with electronics

there should be be other people that know all about Jeep timing chains, the XJ has a pretty robust looking arrangement..the GM Alloytec not so much

 

So from what I can gather, the P1391 has occurred on 2 entirely different engines (except for the flexplate)? You put new sensors on the old engine, but reused them on the new engine? What year is the replacement engine?