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diagnosing engine vibration

8mud, the reason I swapped most of the sensors is because there had been an engine fire before the rebuild. Many of the sensors still worked fine, but it had been my intention all along to to put new sensors in a new engine.

If I were just swapping to check things, I would just have a friend with a similar year drive his Jeep over and start swapping out his parts. If one fixed it, bingo, if not, new approach. =)

I just list all the sensor swaps ahead of time so that people don't start suggesting sensors.

But, to get back on topic, so it's been a while since the Jeep ran. I went out and started it up, and it was running a little rough at idle too. In fact, it kind of seemed to have the harmonic. I haven't had a chance to get out, and check the number one cylinder against tdc yet. I did verify that no wires were crossed when I pulled the plugs.

As soon as I can check the distributor, I'll chime back in. My other fear, as I'm pretty sure we double checked the distributor already at the shop, is that maybe the timing chain is off by just a hair.

As for the injectors, the jeep has new rebuilt Ford Mustang injectors and they were pulled and cleaned as one of the first diagnostic steps after the rebuild...did that just after checking fuel pressure.
 
You mentioned motor mounts... I may be way off, but hear me out.

I just replaced my motor mounts with Brown Dogs. In the instructions they state to loosen the transmission mount until the motor mounts are are settled into place and fasteners torqued. Then tighten the transmission mount. If the driveline is a little twisted, but locked into place I'd imagine that could cause a little vibration.
 
OK, been a while since I chimed in on this because I had no place to do any work.

Just got into a new place with a garage and popped off the distributor. Following the directions in the FSM, the distributor appeared to be pointing closer to 6 'o clock than 5 'o clock. I pulled it out, moved it one tooth back and reinstalled it. This time it looked more like 4:30 than 5 'o clock. Also, I scribed the outside of the post the distributor, and when I lined up the rotor, the trailing edge had not quite completely passed the scribe mark. The trailing tip of the rotor was still slightly behind it. I fired it up, revved it, backfired a couple times, and then the idle settled down. But the vibration was almost gone!

So I take it out for a test drive and theengine vibration is significanty reduced, but I also can't get it above 60mph without it coughing and bucking. =(

This does make me think it is more ignition related than fuel pump related though. I would believe it was the fuel pump more if the stumbling didn't die out. The vibration really strikes me as a harmonic vibration in that it appears and disappears at rpm and load, but it always does it under the same conditions...i.e., same speed on different roads. (but no, it's not the road because it will do it in park too).

On a side note, it went to smog about a year ago, right after the rebuild, and it still had a tough time passing because of NOx. The guy said the temp would look good until the second test, then it would just slowly keep climbing out of range.

I'm wondering if it's just a little too advanced. Since I can't adjust my distributor, would that mean an error in the timing chain installation?
 
I was thinking timing chain 15 lines before I got to the end of your last post!!!
 
Ok, so started to pull stuff off today. since I can't get the engine out, I'm planning on removing the whole front grill assembly, the radiator, etc. so I can just pull up a chair and work directly on the motor...I know, it's a lot of work, but I don't want to mess around with trying to reset the timing. So it's gonna be another bit of time before I get back with any results.

But on a side note, as I began removing stuff from the engine bay to get started, I decided to yank and toss the whole cruise control system. At which point, a gave the old A/C compressor a spin and it sounded like it was missing a bearing. So, since it doesn't work, it's noisy, and the tubes get in the way of everything, figured I'd toss it in the trash heap as well, but how do I clear the system of the R12 responsibly?
 
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Ok, got the whole front of the Jeep pulled off, removed all of the A/C crap, and got started on the timing chain.

I made sure I was at TDC on the compression stroke, I pulled the harmonic balancer (but when I did, it started to turn a bit, so I moved it counter clockwise back to the TDC position, however, it left some slack in the chain. =(



But this is what I can see now.

Should those two indents be 180 off from each other? Or should they be pointing at each other?

I'm thinking that's the problem, just not sure. Any suggestions?
 
I guess I should note that I was following a write up on NAXJA from Jeff in VA.

His instructions said to line up the TDC with the rotor...which I did, and which came after the compression, so it made sense. but if the cogs will only go on one way, did I just have the distributor 180 degrees off? Because the next TDC they match up perfectly.

So maybe I misunderstood, but when they say, "TDC on the compression stroke", do they mean at the beginning of the compression, or at the end of the compression? I always figured end because that's where you'd want the spark to fire, once the gas had been compressed. But from what I understand, the gears only go on one way, so how can it be 180 degrees off?
 
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OK, so while I'm waiting...(I can't believe you people don't sit by your computer waiting for me to have a problem)...I tried desperately to find anywhere in the FSM that it said the distributor should be pointing at the #1 cylinder while these two marks met. But I just couldn't find it anywhere but the walkthrough I was following. However, if we assume there is only one way to put these gears on, which is what I'm reading over and over, then by the FSM, everything checks out. At TDC on the exhaust stroke, the two dots line up. If I rotate until the dot on the large gear is at 2:00, then count the pins, as it says in the FSM, I get 15 pins between the two which is what it says it should be. All the videos then show that I was correct in that I should wait for air to blow, then set the engine to top dead center, and then point the dizzy at position #1.

Now the new news...before I totally disassembled it, I had drained the tranny fluid. I tried starting it up to make sure that everything was back to the way it was before I started diddling with it. The Jeep still ran like crap, but when I pulled the plugs, the #2 plug was wet with gas...I'm wondering if the rotor/cap/plugs/coil have something to do with it. It tend to think it isn't the coil, but the wires may have too much resistence, or the steel rotor and cap may not be conducting enough electricity. However, I also heard several bangs come from the tranny area whenever I'd rev it a little, so I'm back to thinking it might just be tranny related issues.

Anywho, unless someone can tell me that I'm wrong and the cog on the camshaft needs to be spun 180 degrees, I'll just have to wait until the new cap and rotor with brass fittings from summit, the accel spiral core wires, and the new pulley to replace the A/C show up and see how it runs.

Should of just ran the old engine till it died. =(
 
"
OK, so while I'm waiting...(I can't believe you people don't sit by your computer waiting for me to have a problem)..
LOL!!!

I read an old thread with a similar story on the gears, I think you are OK, but I am not the expert.

The gas on the plug is the clue you need to follow. Is it just one plug with gas ? If yes, the spark plug, the secondary wire to that plug or the injector is likely the problem, or all of the above :eek: assuming the compression is good.
 
Yeah, I kind of skipped over it because the cap/rotor/wires were all brand new during the rebuild, so I took it for granted that they were good. But then again, they got introduced at the same time as the problem.

As for the #2 cylinder, it seemed to be the only one. I pulled all the wires off and put them back on, not necessarily the same way because they seemed to fit better this time. With each wire I made sure it popped all the way on and spun it around a little to get a good contact. Started it up and it backfired and sounded like it wasn't running on all the cylinders. Popped off the #1 plug and fired it up; it ran worse. Pulled the number 2 plug and fired it up, no difference. Plugged it back in, fired it up, ran better...but as I mentioned, I started hearing noises in the tranny with no fluid so I shut it down. It has to come off to replace some seals in the front anyway.
 
I think if the Tran fluid is low enough, they can make noises. I think I have seen that with other vehicles several times.

I would test the plug wire with an ohm meter, compare to say #1 plug wire, replace the spark plug, or swap #1 and #2 plugs. Check the oil for gasoline odors now. Then if they are both good (and if compression is OK, might test it any way, might have damaged rings since it is new, or overlooked something in the build, this is a new-rebuilt engine?)

Then if those are all good, get a new injector, as it sounds like the injector is leaking, not closing and sealing completely. A fuel pressure test for 10 + minutes, install the gauge, run the engine, power down and see if the pressure holds might confirm a leaker first.
 
Yeah, it's a newly rebuilt engine. I have about 2500 miles on it. The vibration has been there since the rebuild, but each time I was able to find something, like a loose nut on an engine mount, a trashed transmission mount, switch from poly to rubber, and with each move, the vibration got less and less. The mechanic that rebuilt it swears it isn't an engine problem.

The #2 plug only got wet since I moved the distributor this time around. I moved it back one tooth, tried to run it but it had no power. Then I moved it back to it's original position and started to verify that everything was back to normal. But it didn't run like normal, it ran like crap, like it had a misfire. I think the only reason it's wet is because the plug wasn't firing at all. It hasn't shown that symptom since the rebuild, and removing the plug wire from the plug and reinstalling it seemed to fix the misfire issue.

But that also got me thinking that if a plug wire is that sensitive, maybe one of the internal connectors isn't the best.


...so I just pulled the ohm meter out:

Coil wire - 0 Ohms
#1 - 0 Ohms
#5 - 0 Ohms
#3 - 0 Ohms
#6 - No reading
#4 - 0 Ohms
#2 - No reading

By no reading, I mean when I hit the electrodes to the opposing sides of the plug wire, the guage didn't budge while the others bounced off the 0 Ohms side.
 
well, tested a third time and they all got readings =(

The two that didn't give readings initially, now give uneven readings though. The other 5, I can move the needle all around and it stays at 0, but with the two in question, depending on where I'm hitting it, it can be 0, 100, 200, or just no reading at all.

So I'm back to hoping bad plug wires.

new cap, rotor, wires, and the A/C replacement pulley should all show up this week and I can slap it back together and try more stuff.
 
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OK, so I did enough research to find that it wasn't uncommon for the points to be 180 off, so I ditched the timing issue. Then it became a tranny issue. I put the engine back together with new 8mm plug wires and a summit cap/rotor and all new gaskets. It looks much prettier! =)

So off to my previous concern, the vibe was caused by an improperly indexed torque converter....after all, I knew from the mechanics own admission that he didn't index the TC when he removed it.

I get the tranny almost all the way out and am having problems getting the dipstick tube out...so I stick some vice grips on it, lightly tightened so it catches the lip on top, and give a good yank, and off she comes. Now the TC/flexplate bolts are out, all the electrical connectors disconnected, tranny and t-case linkage disconnected, and the only thing left is the last 4 tranny bolts. So I break loose the 5/8 bolts on each side and then configure my jerry rigged 3' extension, including several 10" flex extensions and a bit of duct tape along with my newly purchased E12 socket. But for some reason, I can't get the socket to engage with the bolt, it just keeps spinning freely. So I reach my hand up and try and get just the socket on. Dontchaknow, the damn thing wasn't even finger tight, it was sticking out by about 4 or 5 threads...so I go to the other side, same damn thing. Guess the mechanic forgot to tighten those.

so I yank the last four bolts and go to pull the tranny, but something is stuck...turns out there's one more bolt that mounts from the dust shield to the tranny on the driver's side. so I get that out, and out comes the tranny.

then I look at the flex plate....it doesn't look like all the markes from where the TC mount are equal...by that I mean, two spots you can see the entire outline of the TC mounting block, another shows only partial, and the final, you can't even see it. =(

I'll get pictures later, but I've resorted to heavy drinking for now...
 
one question though...since the flexplate was kind of funky, and the holes look a little wallowed out, I was going to slap in a new flexplate since it's already exposed and pretty damn cheap. My question is, if I put in a new flexplate, does indexing even matter anymore?

and what if I get a new TC as well? I've heard a miss can screw up a torque converter over time, I've been driving for two years with the dang thing improperly mounted, I'm thinking it's trashed.
 
To be honest with you, I am OCD and mark everything when I take things apart, but as you point out, when you replace an item with a new part you have eliminated any index markings.

Just go for it.
 
OK, so just to bring folks up to speed...

Once the TC was off, I realized the wear pattern on the flex plate from the 4 pads wasn't even and the holes in the flex plate appeared to be wallowed. So I got a new ATP flex plate and got it installed. I also yanked the torque converter off to change the front pump seal, and looking at the torque converter, you can see multiple grinding marks, as well as burned marks and feel grooves in the metal.

So now I've got a Pro-King J30 TC, new bushing, and new oil seal on the way from O'Reilly's.

Anyone have anything else I should be looking for while I'm in it?
 
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