Distributor Noise

[flint54]

Symptom: "ert" - "ert" - "ert" loud chirping when first starting the motor

It goes away completely after a minute or so.

 

I thought it was the tensioner pulley at first, so I pulled it and replaced it

as it felt a little rough. No joy.

 

Got out the old shade tree stethescope (a 24" 3/8" drive extension) and probed

all the logical places. No joy.

 

Then I noticed the sound was well aft of the belt plane, and discovered it is

the distributor. I know they're not really rebuildable (based on parts manual

not listing any bushings/bearings). My question is, before I just go buy a new

one, are there any upgrade options, given the opportunity? Thanks!

[Pete M]

bone-stock ones work great. :) since the computer sets the timing, the dist is just a conduit for the spark.

 

sounds like the gear teeth might be worn. :(

[carnuck]

Could also be the thrust washer on the dist is MIA (between the gear and the housing)

[flint54]

Replacement dist on the way, will post results when done.

Very surprised, given the low mileage and easy life, but

stuff does wear. I know this dist has never been removed

so will be interesting to see if anything is missing. I'm not

sure how far (if at all) oil comes up the shaft, but my hunch

is a worn bushing that gets quiet after a minute of lubrication.

[Jeep Sarge]

Could also be the thrust washer on the dist is MIA (between the gear and the housing)

 

 

dead on, i have had to replace two on 4.0L's you could have replaced, re worked yours but you will never hear the annoying squeek again by replacing it.

[flint54]

Well this has turned out to be a much greater debacle than I envisioned!

 

Got the new distributor today (Morris 4x4 - great folks - rocket fast shipment).

 

The swap was uneventful, but it ran like a dog for a couple minutes and quit.

I'm very confident I got it positioned correctly, but I rotated one spline in either

direction just to double check. Nothing. Want back to basics, pulled #1 plug,

rotated to TDC on compression stroke, and verified rotor pointing to #1 plug wire.

Triple checked wire firing order, 153624. Tested coil and shows strong spark.

Tested each plug wire and getting spark to each plug. I have ~40 psi fuel

pressure at the rail. No spit, no sputter, no nothing. CPS is nearly new.

Only fault codes are 12 (recently disconnected battery) and 52 (running rich)

 

What the Heck is going on here?!? :headpop:

 

BTW, the old distributor was so bound up internally I could hardly even rotate

the shaft by hand.

[Jeep Driver]

I looked at an XJ last week with a 4.0 and among several other problems the distributor shaft was bent to the degree that you could actually see the cap wobble as it ran.......also made a clicking noise similar to what you describe, couldn't imagine what bent the shaft.......I passed.

 

Just curious though......I have put the button in the wrong of three holes in a 4.0 dist and got a no start......could that be your case?

[flint54]

What button? What three holes? Not sure what you mean.

 

I don't think the old dist was bent, just galled up fiercely.

[HOrnbrod]

The button is old school term for the distributor cap center contact to the rotor. Since the cap is keyed to only install one way, ?? No idea about three positions.

 

Recheck the wires again to be sure, firing order 153624 and the distributor rotates clockwise. Sounds like it's not right.

[Jeep Driver]

The button is old school term for the distributor cap center contact to the rotor. Since the cap is keyed to only install one way, ?? No idea about three positions.

 

Recheck the wires again to be sure, firing order 153624 and the distributor rotates clockwise. Sounds like it's not right.

 

 

http://tomasz.korwel.net/2006/12/19/rep ... l-engines/

 

If you look at pic 8 you will see other hole that look like knock-outs, the one to right of the button pin hole was open and I inserted the button pin in that one causing the no start.

[cruiser54]

Try this:

 

http://www.angelfire.com/my/fan/dist_index.html

[flint54]

Thanks for the replies, and for posting the dist. alignment process. I had

already worked through that via FSM, but those visuals are better. So here's

the rest of the story. After a bit of prayer, and a few hours sleep, clearer

thinking returned and I was led to look for really dumb simple stuff (those are

usually the gotcha's right?). Ive been messing with "button"s for many years

but never knew that term. I have a couple new, but unprintable, terms. Turns

out the metal tab that rides on the contact inside the cap had very poor, and

intermittent, contact. That's why I was able to see spark at plugs but no run.

Wasn't getting spark at every plug every time, but only every plug once in a

while. Didn't realize that when testing individually. Once I bent that thing

higher up, voila - running truck. I love simple solutions, but I love them a lot

more when they don't take all night. About the old distributor, I may be

able to resolve it by soaking in penetrant. There's a lot of gummed up fluid

inside, as if oil had found it's way all the way up the shaft over time and then

congealed. BTW this dist is a newer flavor with notched shaft so the button

can only go in one position. The older style has potential to install more than

one position.

[Jeep Driver]

Thanks for the replies, and for posting the dist. alignment process. I had

already worked through that via FSM, but those visuals are better. So here's

the rest of the story. After a bit of prayer, and a few hours sleep, clearer

thinking returned and I was led to look for really dumb simple stuff (those are

usually the gotcha's right?). Ive been messing with "button"s for many years

but never knew that term. I have a couple new, but unprintable, terms. Turns

out the metal tab that rides on the contact inside the cap had very poor, and

intermittent, contact. That's why I was able to see spark at plugs but no run.

Wasn't getting spark at every plug every time, but only every plug once in a

while. Didn't realize that when testing individually. Once I bent that thing

higher up, voila - running truck. I love simple solutions, but I love them a lot

more when they don't take all night. About the old distributor, I may be

able to resolve it by soaking in penetrant. There's a lot of gummed up fluid

inside, as if oil had found it's way all the way up the shaft over time and then

congealed. BTW this dist is a newer flavor with notched shaft so the button

can only go in one position. The older style has potential to install more than

one position.

 

 

Yes that's what I was getting at.

 

 

Glad you got it straightened out and running.

[flint54]

Well it's not over quite yet.

 

Now after ~600 miles, still have an intermittent miss that's

vexing me sorely.

 

Only happens between 2000 and 2500 RPM, moving down

the road. It's as if I turned off the key for `1/4 second,

like a quick cough. It happens about once every few miles,

whether or whether not under load. All the following are

new: coil, distributor, cap, rotor (button), wires, and plugs.

 

All connections to dist and to coil are clean and firmly tight.

 

Sitting still, I can rev it to redline repeatedly without a miss.

 

Have good fuel pressure and delivery, injectors nearly new.

 

Any ideas where the heck to go next? :hmm:

[HOrnbrod]

Mine did that for about a week then died completely. Turned out to be the ignition coil. It was a fairly new MSD coil too. Replaced it with the old original Mopar coil, it never happened again. Try a resistance check on the coil.

[flint54]

Will check that when I get back to FL, but it's a brand new

coil, from NAPA. Did same thing with the old coil, so, if it's

the coil, it's both coils doing the same thing.

[flint54]

Ok, I've tested both coils, and both are within FSM spec. Primary at 1.1 ohms

and secondary at 11.5K ohms.

 

I keep reminding myself that my intent was improvement, by updating to the

newer intake and replacing a troublesome distributor. It's been all downhill

since then.

 

Intermittent miss, with all new ignition components, reworked head, and newer

intake. Also, when I suddenly release the throttle the idle drops to near zero.

The IAC is new and the TB is new and clean.

 

Idle vacuum symptom: Steady at 18-19, then slowly (15 seconds) climbs to 20,

the idle speed drops a couple hundred and the vacuum drops quickly back to 18.

Will do this pattern all day long, all by itself.

 

Will rev to redline smoothly (without load), but with load it sometimes sputters first.

 

No, I don't have AF meter yet, but plugs indicate reasonable mix (lt brown). (unlike

the black I got before backing off the AFPR).

 

I've checked and rechecked for intake leak with propane and no indication, but I'm

about ready to pull intake again just to look at the (new) gasket for any sign of

bypass.

 

Any other suggestions (not involving explosives) are most welcome!

[Pete M]

had a similar problem with my van. turned out to be a dying cps (cam position sensor in this case)

[flint54]

Pete, How I wish that's what it was, but that also is new,

replaced while I had intake off, taking advantage of the extra

room opportunity.

[HOrnbrod]

Have you checked fpr fault codes lately? Unplug the ECU connector and check for any recessed pins. Spray with contact cleaner and reseat. :dunno:

 

Seems like all this started after the intake swap, correct?

[flint54]

And the outcome is...no joy.

 

No fault codes, other than 55.

 

I pulled the ECU plug, and found very little

oxidation. I treated both plug and all pins

to a liberal dose of "deoxit", and scrubbed all.

I verified all pins are correctly positioned, other

than the 10 of 60 not applicable to me (per FSM

schematic). I also verified continuity, and no

resistance, of the conductor (#19) between ECU

and coil. I even swapped in yet another, this time

OEM, coil. I still have a dramatic, and intermittent,

miss under load. When the miss happens the tach

also blips, suggesting to me this is electrical (since

tach feeds from ECU). The miss happens now at

2K(sometimes), 3K (nearly always), and 4K (sometimes)

RPM. Feels as if I momentarily unplugged the coil.

 

Yes, installing the "upgrade" intake manifold was the

genesis of my troubles. I am sorely regretting my

inability to resist the temptation. Could not leave

well enough alone. Lot's of new power, but a totally

unacceptable downside.

 

One interesting observation, the build of my truck is

11/91, but the sticker on the ECU is 01/93, suggesting

that it was replaced (warranty job?) during the first

year of operation.

 

I cannot imagine the ECU being the source of this issue,

particularly since it was initiated by a completely unrelated

(manifold) exchange, but I am rapidly running out of things

to suspect.

 

Also, not sure I mentioned this before, when I suddenly let

off the throttle while in motion the motor will nearly, and

sometimes actually, stall out. Idle is no longer reliable.

 

I used to count on my ability to diagnose/resolve stuff like this,

but not this time. Totally stumped. :hmm: :hmm:

[HOrnbrod]

Well, I'm stumped too. :dunno: I did this mod with absolutely zero problems, as well as many many others over on the stroker forum. It improved the idle immensely and it never missed under load. About 1K miles after, I hard-wired in a Unichip and then had it tuned and dynoed at Hesco. On the way home it skipped a couple of times under load (like the coil was unplugged momentarily) on long grades at about 2500 RPM. Brought it back to Hesco and they set the timing curve back a bit for that RPM range and haven't had a skip problem since. I did notice that after the intake manifold was installed and I disconnected the battery to do some electrical work, the ECU "learning curve" sometimes took up to 50 miles, longer than it used to. It never skipped, but the idle was low and it would stall at a stop at times. But after 40-50 miles or so, all was well.

 

I'm suspecting your ECU now. What's the number on it? I'd also ask this question over on the stroker forum - someone may have experienced similar problems after the intake swap.

[flint54]

My ECU is 56027396 (for 1992 manual 6 cyl).

 

Today I scoured the JY, and grabbed an ECU

from a 92 XJ, auto (all I could find) #56027488,

hoping for good interchange.

 

Well I put it in and truck runs like crap, even worse

than before. Plus triggers maint light. Stumble, miss,

cough, sputter, and stall unless I keep my foot on it.

[Jeep Driver]

There is another thread here where the poster was complaining of a loss of power after installing a replacement distributor.

[flint54]

Didn't see that one, was there a solution? I'm really doubtful the distributor could

be the culprit since it only has one correct position, and since the motor will rev

when sitting still, up to around 4K rpm before getting ratty. I swapped back in

my known good OEM CPS, to rule out a faulty replacement CPS, and no change.

I also found a connector under the ECU that plays in this circuit, opened it up

and found a bit of green,.Cleaned it well, but that wasn't the problem either. There's

an outfit I found online that offers an ECU testing/rebuilding service, but it's pricey

and I'm curious if anyone has used this service:

http://www.directauto.com/product-exec/ ... ng_Service

The want $100 to test, and $228 to repair if damaged. The ECU for automatic (488) doesn't

play nice in the manual, and I had no JY luck locating a 396 ECU to try. Over

on stroker forum there's some discussion about stumble @4200rpm due to

valve float, but those folks are running cams with rapid rise. My cam is, and

shall forever remain, stock.