DurtyGirl91

Evening all,


Been a while, been running strong..


So the other day, after swapping in some new upper and lower ball joints, I FINALLY traced down the clunk I was feeling in the floor- Exhaust at the tranny mount bracket was hitting the frame.. just clunking away..

Tranny mount is shot, causing the attached exhaust bracket to sag, so I'm thinking ok, gotta get that swapped out. NOT the only issue come to find out.
Driving to pick up my daughter, the engine just cuts out. Like a ghost. No bucking, no choking, just dead. All the lights stayed on, nothing dimmed, motor just cut off. Popped it in neutral, started right back up..


A few minutes later, steering wheel starts to get stiff, motor almost cuts out again, but catches itself, and keeps running. Now I'm in survival mode. Gotta get the kid and get home. Going over some bumpy road, cuts out completely again, starts right back up, get home safe.

Could the bad mount be throwing off the position of the CPS, are have some affect in the reading it's taking, and causing the motor to cut off?

New Napa CPS, replaced in July. Have the OEM in my parts box (wasn't the issue..long story). Tested the CPS this AM before taking the train to work, infinite resistance across terminals B and C.

Swapping out the mount tmrw, but any input on this intermittent stall would be greatly appreciated!!

houstonnash10

I had the same cut off randomly issues as well. I ended up replacing both CPS and TPS, plus 2 of the front O2 sensors, and Ragnar, my jeeps names cranked right back up and hasn't died since. knock on wood.

Ive never heard of a tranny mount causing CPS issues. But I did have a question in regards to the Clunking sound of the loose exhaust bracket. Did the sound happen consistnely over bumps? and did it sound almost hallow?

Hope you got it figured out, considering this was months ago. haha

DurtyGirl91

Hey Houston! Good to hear it's running well. I posted this tonight!


I only have one o2 sensor, upstream, no cat, straight to my muffler, side exhaust, gonna check the wiring and sensor for damage here soon, replaced it about a year or so ago, not even sure if it's needed..


The TPS is on my list to check as well, cleaned it up in July as well.


As for the clunk, check your sway bar linkage and bushings, just cut off my rear last weekend. Check your track bar as well for any play, PM me if you want more info on the sway bars!

houstonnash10

Oh, sorry. haha I read your original post wrong. I thought you had posted this in July! haha

Your o2 prolly isn't the issue then. Considering you only have one that is recently replaced.

I had put a brand new TPS, much easier to get to than the CPS. but yea, both of those should do the trick, unless you have a greater electrical problem.

The Clunk: My sway bars are pretty much brand new Qdisconnects on the front, same OEM on the rear though. Adjustable Track bar has some play on the internal threads, but that isnt where the sound is coming from. It is the loudest, and most hallow, over bumps at 30-45mph on, or around the passenger side wheel. I felt for play in just about every steering linkage part and saw a bushing busted wide open on the drag link, dampener side. Could that be causing that sound??

cruiser54

Check the wires to the CPS. Maybe they're grounding out on the exhaust manifold now.....

DurtyGirl91

Always helpful Cruiser, thanks!!


Finished swapping in my OEM CPS, the original, as when I swapped in the NAPA one in July, turned out it wasn't the problem- And the difference between the magnetic strength of the OEM sensor and aftermarket is undeniable. Still not sure if this is the issue yet. Waiting to bring the jeep up to operating temp and see if I can get it to fail again.


Cruiser, should the pigtail not be touching any part of the manifold, to avoid grounding out? It still has the protective plastic sheath.. Thanks again for the input!

jordan96xj

As you diagnose, be careful not to tunnel-vision on the CPS. On a 91, the fuel delivery (pump/regulator), ignition coil, and or general electrical connectivity (ground connections), are just as likely to cause a full shutdown like you report.

No matter what, I would start with a general servicing of all the electrical connections under the hood. As I got into that, I'd throw some gloves on and do a "shake" test on the various harness bundles while it was running, to see if I could cause a shutdown or any disturbance in the motor's running. (basically what cruiser54 is suggesting)

If you could firmly say that this only happens after reaching operating temperature, then I would prioritize the items under the hood (coil, CPS, fuel regulator if it is the kind that is on the rail, and general wire/connection condition). The fuel pump motor would not immediately be sensitive to operating temperature, unless it was an electrical problem stemming from the power distribution center, relays, etc as they got warmer.

I'm also thinking that the steering wheel going stiff was only a symptom of the engine RPM dropping to a low level when it was trying to die. That would be purely mechanical. Unless it ceased so bad that it stopped the motor (not likely, without ruining a fan belt, and making a huge racket).

Good luck, and drop a message here when you learn more. I'd like to follow it.

houstonnash10

Jordan96xj with clutch info.

That is a great post too go through all possibilities. With mine, those two replacement of the TPS and CPS fixed it. I'd also like to know the outcome.

good luck!!

DurtyGirl91

Evening all. And thanks for keeping me out of the tunnel Jordan. I refreshed all of the grounds, and swapped the OEM sensor back in. No more stalling. However. I think an underlying issue here is the ignition system. While checking the wiring under the hood I noticed that the wire from the camshaft position sensor in the distributor is getting pretty worn, some cracking in the rubber wire shroud, and it runs right along the block, so I'm sure it gets pretty warm. My 3 month old NAPA started also died the day after I got the transmission mount replaced as well. Straight up DIED. They swapped it for a new one, no questions asked.


Pair the CPS and Starter failures with the heat soak I've been experiencing ever since the cold weather has passed (60 degree February weather in Chicago; Global Warming..) I've got some work ahead.


Plans:


-Replacing the 26 year old OEM Ignition coil, ordered my new Mopar unit from Morris 4x4..


-Replacing the Camshaft position sensor in the distributor, and rerouting the wire away from the block.


-Changing coolant.


-The link below provides detail on installing a timer for the efan. The timer is activated by a switch that runs the efan for 2.5-3 minutes after shut down. I have an 8.5x 3 inch hood vent installed in the top right corner of the hood, over the brake booster/master cylinder. I haven't decided if I want to set up a SPAL 4 inch pusher fan under the right side of the vent, set up to run on command, and via the timer switch after shut down. OR just run the efan via the timer, and leave the vent completely open to serve it's purpose, cycling out more hot air with the help of the efan.


Short response here, I had a spare CPS, and swapping it in has stopped the intermittent stalling- for now.


Thinking the underlying issue here is a combination of heat soak and worn ignition system components. Thoughts and input here will be appreciated! Thanks guys!!


Efan Timer How To:
http://naxja.org/forum/showthread.php?t=1028190