I also had a bolt back out of the flexplate in my old XJ. It sounded a lot like rod knock. It's probably a long shot here, but if you're going to check the flexplate, it might be worth throwing a wrench on the bolts while you're in there.
I also had a bolt back out of the flexplate in my old XJ. It sounded a lot like rod knock. It's probably a long shot here, but if you're going to check the flexplate, it might be worth throwing a wrench on the bolts while you're in there.
Try some Teflon tape on the bolt threads.
The knocking may be a bolt on the flex plate backing out, or the flex plate itself coming apart. It is a fairly common occurrence when the engine has been out of balance on MoPars, as the flex plate is pretty flimsy.
I would use a long socket extension as a stethoscope to try to pinpoint the location of the sound. Usually rod bearing issues will show up in the oil. A piston issue is also a possibility with an engine that old.
+1 on cooter and jermeyJ comment.
Next time I have it on my buddy's lift, I'll check out the flexplate situation. I've never had a knock end up being the flexplate, but you never know.
In other news, I took the truck out for a lengthy cruise a couple days ago. It's definitely driving a lot better with the tweaked tune, although I do need to adjust the overall fuel map a bit. Happened to drive by one of my favorite photo spots, so I stopped and took a few shots.
Today, I decided to try and tackle the non-operating dome light again. In previous installments of this saga, I fired up the Parts Cannon and replaced the bulb, the door jamb switches, and even the headlight switch. None of those helped. But what I had this time that I didn't have before was a shop manual with a wiring diagram. So, I traced the wires and found this:
That pair of pink and white wires, yeah, the ones with the EXPOSED WIRES, are the ones that go to the dome light. I cut back until I found clean wire, and connected them back together. And yes, I know the floor is ugly, I'll get to that later on.
And it actually works. Color me shocked. Something went right for once! I know it's dumb, but driving at night sucks without a dome light.
Quick update:
Tackled that leaky water pump bolt. Again. For the 5th time, I think.
This time, I drained the radiator, pulled the bolt, dried out the hole, cleaned out the gunk, and used teflon tape instead of liquid sealant. I went heavy on the back end of the threads, and I think that helped. Leak has stopped, for now. Anything liquid wouldn't seal, but the tape seems to do a better job.
Also, I think my new water pump is already making bad noises. It was squeaking and making creaking/knocking sounds on startup, but quieted down after running for a bit. I'll have to keep an eye on that.
It's been a couple weeks since I updated the thread. Basically, I've been driving the truck when I can, and messing around with tunes and things. I got it running OK with a few small hiccups I need to iron out, but overall it's running better than it ever has.
A few nights ago, I was out running some errands in the tail end of a bad Nor'easter that came through here. There were a lot of downed trees and branches on the roads, so I opted for the ground clearance of the Power Wagon instead of the Forte GT. I was right about to pull into my destination and my wipers folded over each other, breaking one of them. Perfect, just what you want during torrential downpours! 
Both wipers would not move, so I limped it home slowly and carefully, and I may or may not have had my head out the window Ace Ventura style. After doing some research, it turns out old Mopars are notorious for doing this. The linkage is connected to each other with plastic bushings, which love to crack apart over time. Good news is the parts store stocks the bushings, so I ran out and grabbed some along with a pair of new wiper blades.
Fixing it is simple: You pull the arms off, remove the cowl panel, pull the linkage out, replace the bushings, and re-assemble.
After pulling the cowl, it was easy to see what failed: the bushing crumbled off at the driver's side wiper, and the rest of the linkage extended itself further than it should and got stuck on the motor arm, locking everything up. Sorry for the potato pic, but it was a tough angle to get!
The linkage assembly is pretty easy to remove in one chunk, including the wiper pivot arms. Since mine were busted off, I removed them separately. The holes in the linkage are all supposed to have bushings, and there were two that were completely missing, There was also evidence that the Wire Nut Bandit had been in there, because instead of a bushing holding the linkage onto the wiper motor, I found a pair of washers and a snap ring. A valiant effort, but puzzling considering the bushings are widely available. Either way, I replaced all of the bushings. Pro Tip: GRM'er and all around Mopar master Cooter clued me in on this one. Soak the bushings in hot water prior to installation. This makes them more malleable and easier to install. Thanks Cooter!
While I was in there, I noticed that the corners of the cab were missing seam sealer. I've been getting leaks in the cab since I bought the truck, and now I know why. Luckily, I had some seam sealer in the garage ready to go, so I cleaned up the area and gooped up the holes. Hopefully that stops the leaks.
Not sure if this screen is factory or an old man hack, but it came off in three chunks. I cleaned it off and re-installed it. Definitely leaning toward the old man hack on this one, but they were smart to install it. The inside of the cowl was free of debris!
And done. I made note of where the arms were when I pulled them, and this is where they wanted to be. Wipers do wiper things again!
Last time I was out in the truck, I noticed that the heater controls felt a little weird. Last winter, I had to fix the heater hoses and reposition the heater control valve, and while doing that, I realized that the cable wasn't connected correctly so I fixed that. After looking at the valve while operating the heat controls, I noticed that I could only move it one way. After fiddling with the cable and controls for a bit, I heard a snap.
The cable broke at the heater controls. D'oh!
I should be able to remove that cable chunk and insert the cable again. I think that when I replaced the hoses and moved the valve, it left too much slack, so this is the truck self-correcting. At least I can manually move the valve for now so it has heat.
In reply to Tony Sestito :
That's the most disheartening sound ever also.
I keep seeing these first gen trucks popping up on FB Marketplace, but I'm already in a bind on having to find a new place to keep one of my projects... ugh.
Today, my company gave us the day off since it's Veteran's Day (THANK YOU VETERANS!) so I did the most American thing I could: change some fluids on the Power Wagon.
On the agenda is a transmission filter/fluid change and to change the transfer case fluid. I've been meaning to do that since I brought it home, and the trans pan gasket has been leaking a lot, so it was time. First, let's do the transfer case.
This is dead simple: pull the fill plug with a 9/16 wrench, and use the box end to remove the bottom-most bolt. That bolt serves as a drain hole.
Stinky, gross fluid of an unknown, incorrect viscosity came out. I let it drain for a good while to get as much out as possible. These old NP203's take regular ol' 10W30 motor oil, and what came out was stinky like gear oil. Guessing this was changed in the past and the Wire Nut Bandit used whatever gear oil he had on hand. It was also about a quart low, which is also not great.
Not sure why I didn't own one of these before, but this is the only way to get the fluid in there. No pics, but I pumped about 4.5qts in there before it was coming out the fill hole, so I sealed it up and called it good.
Next, dropping this moist, gross pan. It has a swollen cork gasket that's been on there for probably decades, and it was seeping out everywhere.
There. Wait... what is in the pan?
Is that... SAND?
AND A CHIP OF BLUE PAINT??? HOW???
Magnet had little sludge on it, so at least that's a good sign. But yes, I found SAND and a PAINT CHIP in the transmission pan. Your guess is as good as mine. All I can think of is the Wire Nut Bandit sitting at some local watering hole in East Armpit, Maine and someone telling him that tossing sand and some of the flaking paint in the transmission will help it shift better. That's the story I'm sticking to. There wasn't a ton of clutch material, and the fluid smelled and looked ok, so that's good. Filter had minor clutch material in it, with a little sand on the bottom, so it did its job. Inside of the trans looked great. I've seen a lot worse.
I was painting some wheels today, and some of the paint happened to make its way onto the transmission pan. After that dried, I popped on the rubber gasket (no more cork!) and bolted it back on.
After the pan was installed, I filled it up and checked for all gears and made sure the transfer case shifted. So far, there's only one neutral, as there should be. The transfer case is still crunchy shifting into HI and HI LOCK, but that may have been because I needed to "bump" the truck to get it to mesh up. Once I did that, it plopped into HI and all was good. I had to do some Truck Stuff this evening, and it seems to drive smoother, which is nice.
It's been a couple weeks now since I found BERKING SAND in my transmission when changing fluids. So far, everything is good. Truck shifts great and the pan isn't leaking fluid everywhere anymore. But of course, there has to be something wrong, otherwise I wouldn't be posting, right?
Last few times I had it out, I went somewhere in it and it was slow to start, as if the battery was dying. Each time, I'd bust out the voltmeter and see proper voltage across the battery, but it would dive to 10 or less on startup according to the Atomic EFI screen. That indicates a weak battery or a bad connection. Wiggling the terminals would get it to start normally, so I'm banking on the latter.
Now here's the thing: when converting to EFI, the kit says to wire a bunch of stuff (specifically power leads and grounds from the ECU and ignition box) directly to the positive and negative terminals:
No, it's not pretty at all. And guess what? When I wiggled the battery terminals, I noticed that some of the wires on the positive side were loose as a goose. I tightened them back down, but I couldn't go too tight for fear of cracking the terminal. I really need a better solution here. Could be as simple as installing better terminals, or as complex as adding a relay block to wire everything to. I was thinking a possible fix would be to replace the terminals with something like these:
Not sure if this would help or not, but I need to do something to make it happy.
Another thing that's definitely related is that using accessories like the headlights, wipers, and blower motor can drop voltage a bit. Having all three on makes things interesting at idle. The low hanging fruit seems to be rewiring the alternator/ammeter circuit, so that's on the list, but think I need to do more than that. Not even sure where to start there.
Check your battery cables thoroughly, the negative cable on my '94 K1500 was shot and caused all kinds of issues. Chevy routed them near a heat source and the cables all break down over time. Your truck is 15 years older than my Chevy was, so if the battery cables are original, they might be due for a replacement. I love this thread, keep up all the good work!
Good timing! I just went through this Sunday afternoon on the J20, as the starter wasn't engaging and the battery terminals were typical featherweight garbage (probably purchased in haste on a Sunday afternoon). This time I was able to get my preferred terminal style at the local McParts (link):
These last forever and make disconnecting the cables really easy (obviously they do require eyelets on the end of the cables). If you don't want to run the wingnuts, you can just back the bolts out and run them in from the top.
The sand might have come from the gasket / pan rail area, external to the trans, but felt into the fluid when you pulled the pan. That kind of external debris getting into fluids like that is common when opened up. Still good to get the fuilds swapped.
Some clarification:
-Both battery cables are less than 2 years old. The originals were shot, so they were replaced.
-Marine-style brass terminals might do the trick. Just need to find some where I can get that wing nut tight enough without stripping out, since most of the ones I find are made of cheap pot metal these days. I'd need to add eyelets to the main cables.
-Sand/debris could have come from above the pan, but I pulled that thing straight down without touching anything up top. Who knows. Regardless, the 727 doesn't care either way.
Tony Sestito said:-Marine-style brass terminals might do the trick. Just need to find some where I can get that wing nut tight enough without stripping out, since most of the ones I find are made of cheap pot metal these days.
On the ones linked above, and I think on every pair I've ever had, the wingnuts thread onto bolts which are threaded into the terminal from below. The tension is between the wingnut and the bolt, not the body of the terminal.
When I spent a summer on a maintenance crew for a rather large construction company, that did their own oil analysis to know when to change fluids in equipment with their own lab back in Omaha, I was told by a master mechanic about how different guys running the tests could influence how the samples came out. We had one guy who was very meticulous, very neat and tidy about everything including keeping his hands clean (literally). We had a second guy who was none of those things. Samples taken on the same equipment by the second guy would come back all "this motor is doomed, oil full of trash, etc". When done by the first guy to make sure things were really as bad as they seemed, the samples came back good, things are fine.
Not saying you're a slob, just saying that stuff runs downhill and gets into places you might not expect.
In reply to pres589 (djronnebaum) :
I was much more concerned with what the fluid looked like and what was on the magnet than that sand/dirt. Both looked pretty clean, and the oil didn't smell burnt or have sparklies in it. The clutch material goop on the bottom of the pan was minimal. I did see some very minor debris on the inside of the trans that couldn't have gotten there unless it made its way through, but that was minimal as well. The most important thing is that everything seems to be fine now.
The engine, however, still seems to have a hell of a knock at idle. I'm still leaning toward exhaust hitting something or something being loose, because it otherwise runs fine. Again, if it blows up, it's Magnum time.
I took DarkMonohue's advice and grabbed some brass marine terminals and installed one on the positive side. The negative side should be OK.
Converted the positive lead to an eyelet...
...And there we go. I still don't like wires going everywhere like this, but at least things are making contact.
The unfortunate part is that I believe that the battery itself is just not powerful enough with the EFI and ignition wires hooked up to it directly. During cranking, it's still dropping down to 10 volts or lower. The only connection that hasn't been replaced recently is the starter relay itself, so I'll be replacing that as well. This battery only has 530CCA, and I just don't think that's enough for this thing. I do have another, better battery from my Trans Am that has 800CCA that is on the charger right now, so I'll be swapping that in here ASAP.
Yesterday, I had to do "Truck Stuff" with the wife, and the truck had trouble starting again. Like before, the battery voltage dropped down in the low 10v range on starting. Not impressed, my wife told me to point the truck toward O'Reilly Auto Parts to just get a new battery.
This one has 800CCA vs the 530CCA on the previous one. While it does crank better, the truck is still dropping low enough to make starting troublesome. I think it's directly related to all of the stuff hooked up on the positive side, so I'll be doing some wiring clean-up. I just ordered a buss block to hook up all those positive wires:
I'll be connecting all of those wires here instead of the battery post. One of the issues is that marine terminal; the wing nut never seems to be tight enough with all the wires running to it, so I'll run a jumper between the positive to here and it should help distribute the load. I'll also replace the starter relay, which is original and probably not helping matters. Hopefully, I can get this sorted out.
In other news, I took the truck on the highway during the trip. It cruised right along at 65mph and kept up with traffic. I observed that timing was on the low side (around 27 degrees near 3000 RPM, should be over 30) so I have some headroom for upping that. It's also using too much fuel during cruise, so I'm working on tweaking that as well.
Having things connected directly to the positive post vs. breakout somewhere 'more appropriate' in the chain shouldn't matter at all as far as voltage levels during cranking. If it did that would mean your connections further from the battery were an issue and there was voltage drop across contacts. A well charged, good condition battery with excessive voltage sag makes me wonder about the condition of the starter.
Maybe some of the other troubleshooters have some thoughts. I do like the idea of getting that stuff off of the terminal itself. I think I'd rather have them all switches so they're not constant-hot.
In reply to pres589 (djronnebaum) :
Starter is less than 2 years old, but the starter relay is over 40. Seems like the low hanging fruit here. I have one, and will swap it in as soon as I can find the damn thing. 
Seeing various online sources saying voltage sagging as low as 9 V (at the lowest) is normal.
Starter relay might be part of the issue but the voltage level itself maybe isn't an issue. Have fun!
Speaking of the low hanging fruit...
That looks less than good.
That's better.
I cleaned all the terminals before plugging them in, and it helped a bit. Voltage seems more stable when starting, for now.
The wires going to the starter could use replacing, so I'll add that to the list. That big 3-plug connector with the red, brown, and orange wires in the foreground also goes to the old EGR Timer circuit, so I'll see about eliminating that from the equation. I think cleaning up all the power wires, cleaning up some connections, and hooking up that buss bar should put this to rest.
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