Dropping a quick note here: Drive home from work was smooth, even with a quick stop at a store and A/C on. Seems coming home in the hotter evening is alright, almost always my problem is in the cooler morning... Seems backwards. Moving along.

Now about that 3rd party crank sensor: Seems fine. Absolutely no weirdness and I almost forgot I changed it, none of the oddities I had before swapping out the one that originally came in the truck. Of course, this is a preliminary, I'll have to see if it weirds out later, but for now: My truck likes this sensor. It's a Herko CKP2016, it's constructed like the OEM one with the two metal tangs at the end, not like other 3rd party with completely capped ends (looking at you BWD, you sucked). The BWD one I tested ran ragged right at the first startup, and within a minute, threw a code and died. This was back when I was chasing a ghost misfire code. Anyway, the herko seems to be doing great, and the wires are pretty rugged, they have some sort of harder plastic-like casing instead of soft rubber. I've actually been impressed thusfar with Herko brand parts, and they're cheap. Currently running 3 Herko branded items on my truck.

The crank sensor was about $14 on ebay, I didn't have high hopes naturally, but even if it only lasts a year? $14 + 15 minutes is worth it to me. Don't always have $100+ for a mopar.
Coil was about $12, no issues from it so far.
TPS was about $9, and the voltage on it reads exactly like OEM mopar I took off (again, all these were when I was chasing that phantom misfire). I actually had bought a Driveworks brand from Advance Auto for about $30, what a mistake. When in OD and the TC locked, the "lower" end was too high (read 21% throttle without touching the pedal, OEM and Herko both read 14.9%) so the TC stayed locked unless I hit the brake.

Not really a plug for Herko, but I can't say I've had a bad experience with their parts, and they've all be really cheap considering. Would OEM be better? Absolutely. If you can't afford OEM, would I recommend? Sure, they've worked for me and have been cheap, yet the construction feels very solid of all the parts.

Back to the issue at hand: Why is it so inconsistent... I hate chasing problems that can't actively be reproduced... Next test is whenever my relays show up. Some things I did notice on the ride home: When not pressing the gas, after about 3-5 seconds, the RPMs drop by 200-300 and makes the truck decelerate, like engine braking, tapping the gas and it jumps right back up. I'm assuming this is a sort of deceleration mode and normal. Other thing I noticed, might be due to the Isumo IAC... Idle in gear is 680, idle with A/C on is 720, idle in park/neutral with A/C off? 1k. A touch high, but not massively, hopefully it'll level out after a few more restarts, only been started twice since last battery unhook. Otherwise, as stated above, it ran perfectly fine this evening. Siiigh, cautiously optimistic: yet depressively anxious.

 

It's a bit hard to tell with how random the stall is. Although I don't think it's actually died if I was pushing the gas, it's never died "going down the road' completely. Only once did it seem to "die" (cruising to coasting feel and RPMs dropped for a moment) before it picked back up, sort of like it tried to die: but like a manual transmission, the rotation "started" it back up. Almost exclusively shutoff if sitting still or stopping.

 

Update: Tossed in new relays, ran about 2 seconds, shut off. Was a little hard start the 2nd time, even tried holding the gas down. Took about another 4-5 seconds before it started, then it idled fine. About to storm, but maybe if I'm lucky, I can get to a parts store and rent a fuel pressure gauge...

Replaced so far:
IAC
CKP
CPS
TPS
Cleaned TB
ASD Relay
Fuel pump Relay

Edit: Tested fuel pressure, turning key it jumps to 50psi, then settles and stays at 40psi even after key off.
VHKCacC.jpg

While running, the needle quivers around 50psi, open throttle stays at 50psi.
Ls2mr0q.jpg

While I was there, grabbed some CRC electronic connector cleaner and talked with the woman behind the counter. She had the same problem in a jeep liberty and it turned out she had moisture in her PCM. So she sympathized with me and gave me 50% off the can of cleaner. $4.99 for a can of $9.99 cleaner? Yes please. Now off to return this loaner tool and get my $150+ tax back.

 

Welp, I might have found the fix. I'm being cautiously optimistic and I won't quite call it "fixed" quiet yet, but no problems thusfar. Even today, ambient temp was 98F, about 65~% humidity, and sunny.
Decided since it was free to try and absolutely no harm in testing it, I did the old Jeep JTEC fix with the case screws. The theory goes that the screws are too long (they're 1/2 inch) and the left one specifically is placed over part of the PCM that controls the spark from the crank sensor. Over time it eventually grounds out, read some plastic bushing deteriorates or the gel inside eventually gets old and flexes the board just enough.

A 'test' for it is to simply unscrew the two torx screws (the two under the harness connectors) about a 1/4 turn or so, or even back them out a bit more to see if it helps. If it seems to work the fixes are:

1: Get shorter screws, about 1/4 inch.
2: Cut the current screws about in half.
3: Add washers for spacers.
4: Just leave them 1/4+ turn out.

I opted to fabricate some spacers from 1/8" black sanalite. So far, not a single hiccup... The best fixes are free: Money I have currently in chasing this issue? $9.21, which was 2 relays + shipping from Rock Auto, which I wanted to replace anyway because of the obvious corrosion. The rest of the parts, I had laying around. If I can go the rest of the week without any more problems, I'll start a new thread with this info so it might help others.

6AIKwYS.jpg

 

No updates in awhile... Why? Because during testing (after my "pcm fix" I put the OEM sensors back in) started the truck, pressed the brake pedal and went to pull the parking brake... Brake pedal went to the floor. Siiigh. Blew the rear steel line somewhere near the rear fitting.

Always something! After about four and a half hours, got new lines ran, had one drip, but seems to have stopped after re-tightening. Need to bleed it, but now I can get back to diagnosing the intermittent shut offs. Unlike the random shut down, the brakes actually took my truck out of service, now I can at least use my truck again.

 

So, the day I bleed the brakes and get them all fixed up. My transmission drops reverse, snapped the rear band out of nowhere. Now everything is back to square one so I can continue looking at my shutdown issue. I MAY have found the culprit... and I hope it is.. Was going to swap my OEM coil pack back on, pulled the wire off the coil and looked in the wire, corroded and rusted to crap. Wires are just over a year old, ~15k miles. I know I put dielectric grease in them, but it was dry and rusted, still had my old wires so I went ahead and swapped out the coil wire. We'll see what happens now before further diagnosis.

EDIT: Nevermind, apparently I hit something and actually "hard killed" it where it wouldn't start back up. This allowed me to do some troubleshooting and I actually found the problem. Had a co-worker turn the key and as it cranked, I gently pulled up and pushed in on the center white connector on the PCM, truck started. While it was running, I gently pushed down and it began to die, pulled it back up, goes back to idle. Did this a few times to verify, then came up with a temporary solution. I'll devise a better clamping method with rubber pressure points to ensure distribution of clamping. Should work for awhile, but it means I do have to keep a PCM in mind.

0G9hUft.jpg

 

Been awhile for an update here, haven't had any shutdowns until the past couple of days, which forced me to (finally) make a more permanent setup than zip-ties and some wood. I suspect the zip-ties have began to stretch from the heat and releasing tension, the horizontal one just slipped right off when I was removing and I was able to salvage all but one of the zip-ties.

I fabricated a new ECM shackle using 1" steel angle bar, two 4" long, 1/4" thread bolts, matching T-nuts, washers, and slide bar from a broken harbor freight quick-grip (they're actually hardened steel!).

ANG1r82.jpg

Here's the "unit" simple, but effective. The angle bar fits around the plugs and ensures they're all held in straight and tight, also helps it not move.

1lkdocm.jpg

And here's one with it all mounted up.

Did this today while at work, and had no problems with my ride home. Will continue to drive my truck until I can say with cautious optimism, mission accomplished... No one really replied to this thread, but posting my methods and whatnot for anyone who might waltz by on google or search and hope it helps them. I'll update in a week or so if I've had any further issues or it seems to have worked.

 

I am reading your posts. Same thing happening to my 97 Dakota. How's it running?

 

Not a single blip after installing the new shackle.