I think my 304 is sick

[tarry99]

Tarry99 thanks for the help but i already had her torn down before you posted.

Just a little update. i did find some aluminum shavings in the timing cover and the little lip above the crank was worn down a little. I still haven't found the tolerance for the edelbrock chain but my fsm says 7/8" is max deflection in the chain i had 1". The new chain is literally just a hair shorter so I'm keeping my fingers crossed but doubt this was the real problem.

I would have had it back together yesterday but wifey decided to fall through the ceiling from the attic so i had to put things away and take care of her. I'll post up if the knocking/ slapping comes back. Otherwise thank you all for the help

Spike

Spike,

First off I hope your wife is doing better...........

I am assuming that you are replacing both gears and the timing chain as a set?
I was hoping that before you tore it apart by checking the timing at the crank and the Distributor that at least you would have a reference point of before and after the replacements...............Let us know if this fixes the problem.

 

[spikey]

Wifey is pretty tough but gave in this morning and called the advice nurse. She will be getting an x-ray on her foot this afternoon..

And yea i bought the chain and sprocket set. Edelbrock performer i think.

Spike

 

[spikey]

I found the issue with the timing chain. View attachment 11543

It looks like some of the pins and ground down which would explain why i had some aluminum shavings in the cover as well. I'm not sure what was really causing that but it its running great right now. Well i have to put some shims back under the grille.. But then all Will be great.

Thanx again for all the help guys. I even took the time to replace a leaky axle seal since i haven't been driving it.

Now to figure out why my rear brakes don't work. Lol

Thank you all
Spike

 

[tarry99]

I found the issue with the timing chain. View attachment 11543

It looks like some of the pins and ground down which would explain why i had some aluminum shavings in the cover as well. I'm not sure what was really causing that but it its running great right now. Well i have to put some shims back under the grille.. But then all Will be great.

Thanx again for all the help guys. I even took the time to replace a leaky axle seal since i haven't been driving it.

Now to figure out why my rear brakes don't work. Lol

Thank you all
Spike

Spike,
I'm glad you found the problem.......When you mentioned that the timing was moving that was a pretty much a good place to start. Some of those OEM timing sets had plastic & aluminum gears and were prone to wear...Hope you found a steel set. That should at least fix your timing issues.

 

[mtnwhlr]

I'm happy to hear you got it fixed

 

[spikey]

Meh.. I hate to keep bringing thus thread back to life but i either did something wrong or there are bigger issues with my motor.

Sunday evening i had it timed at 8 btdc. At idle it was set at 800 rpm. She sounded perfect and on my 10ish mile test drive she did great.

Yesterday i drove my 20 mile commute did good on my way to work. She got a little sluggish up a hill on the highway but nothing major. On the way home going up the same hill she went to . Started pinging really bad and surging. I topped out at 45mph going up the hill.

When i got home and put on the timing gun i had to use my little advance knob to even see the mark. I was way out of time. I know my distributor is not moving. I know that was mentioned in this thread so i marked it

So could i have put the chain on wrong? Possible, but i did line up the timing marks and spin the crank till they met again then checked that the piston was at the top of it's stroke.
Could my cam be going flat? I know it's moving in there cause i had marks on the timing case where it had rubbed. And that could be why the chain was rubbing.

I'm just looking for a little input in where to go next. Valves? I'm a little frustrated so not thinking straight

Spike

 

[tarry99]

Meh.. I hate to keep bringing thus thread back to life but i either did something wrong or there are bigger issues with my motor.

Sunday evening i had it timed at 8 btdc. At idle it was set at 800 rpm. She sounded perfect and on my 10ish mile test drive she did great.

Yesterday i drove my 20 mile commute did good on my way to work. She got a little sluggish up a hill on the highway but nothing major. On the way home going up the same hill she went to poopie. Started pinging really bad and surging. I topped out at 45mph going up the hill.

When i got home and put on the timing gun i had to use my little advance knob to even see the mark. I was way out of time. I know my distributor is not moving. I know that was mentioned in this thread so i marked it

So could i have put the chain on wrong? Possible, but i did line up the timing marks and spin the crank till they met again then checked that the piston was at the top of it's stroke.
Could my cam be going flat? I know it's moving in there cause i had marks on the timing case where it had rubbed. And that could be why the chain was rubbing.

I'm just looking for a little input in where to go next. Valves? I'm a little frustrated so not thinking straight

Spike,

There are only two things that will change your timing, the chain & gear set under the timing cover and the distributor coming loose.

If you mentioned what distributor you had I missed that, but there could be a few other things related to the distributor........one would be the gear on the end of the distributor and whether it is worn or not at the cam gear. The other could be the centrifugal advance plate if yours is equipped with one that is also coming loose...........

You need to mark everything and verify each and everyone of these positions so that when it moves again via a process of elimination you can find the problem.....................or take it to a competent mechanic and get the results that way.

 

[spikey]

Well with a mechanic i wouldn't learn anything. It does sound tempting but when i get my cj running good i will be looking for a willys from 42 to 52 so I'd like to have a little clue of what's going on. I'm not a complete idget i just haven't had to tear into timing quite like this yet so i have a learning curve going on. It's just a curve with a huge radius.

I'm running an msd distributor. Right now i have it set up with the silver spacers, and one light silver spring with one heavy silver spring. Before i tore into the chain i bought a spring kit and replaced the ones i had broke in there. I have put in new plugs, brand new msd wires, cap and rotor as well.
I also have the msd 6 offroad ignition box, msd tach adapter, and coil.
I alsohave an edelbrock camshaft, Carb, intake, and just put in a new double roller timing chain with the metal sprockets.
By looking at the gears on the dist. They seem to be in good shape. I will take your advice on marking every little thing and seeing if anything moves. If not I'll start pulling bolts and check my crank and cam shaft bolts.
Thanx

Spike

 

[57jeeper]

Sounds like valve timing to me.
Back when I was in high school my friend with a 69 charger with a 383ci jumped on it really hard one time too many. It stumbled a lot, had no power and backfired thru the carb.
We threw a timing light on it and the timing mark was now way down on the pulley rather than up on the timing chain cover. We determined that the timing chain jumped a tooth but somehow we were able to get it to run by messing with the ignition timing.
It wasn't perfect, but it ran good enough to sell it to somebody else.

 

[tarry99]

Well with a mechanic i wouldn't learn anything. It does sound tempting but when i get my cj running good i will be looking for a willys from 42 to 52 so I'd like to have a little clue of what's going on. I'm not a complete idget i just haven't had to tear into timing quite like this yet so i have a learning curve going on. It's just a curve with a huge radius.

I'm running an msd distributor. Right now i have it set up with the silver spacers, and one light silver spring with one heavy silver spring. Before i tore into the chain i bought a spring kit and replaced the ones i had broke in there. I have put in new plugs, brand new msd wires, cap and rotor as well.
I also have the msd 6 offroad ignition box, msd tach adapter, and coil.
I alsohave an edelbrock camshaft, Carb, intake, and just put in a new double roller timing chain with the metal sprockets.
By looking at the gears on the dist. They seem to be in good shape. I will take your advice on marking every little thing and seeing if anything moves. If not I'll start pulling bolts and check my crank and cam shaft bolts.
Thanx

Spike,

Believe it or not with a mechanic present you may also learned a few things.
You say you broke the springs on the advance plate before............how did that happen?

Again if you put the timing chain back in its proper location & things are tight...........there really should be no reason to think there is an issue there since it started OK...........I would be looking at that mechanical advance plate in the distributor since you stated there were broken parts you replaced. The difference in advance springs you installed would be questionable but since I'm not there I have no idea why you did that.

And as I have mentioned before in previous threads you should be going back and forth referencing your timing marks at the cover @TDC and rotor location versus the cap at the distributor on #1...........Had you done that you would already know where the issue is.

 

[mtnwhlr]

To me it sounds like something is going on with your timing chain. I say this because you said after you installed a new one it ran fine but after you put some miles on it now it is way off. Does the top gear have a pin that fits into the gear to keep it from moving? And does the crank have a key way to keep the bottem gear from moving? I have never worked on a AMC 304 but every engine I have worked on has a set up like this. with out these parts or something like it the gears will spin because just a bolt will not hold it where it needs to be.

 

[spikey]

Both the crank and cam shafts have a keyway. On the cam i could only put it one way. The crank i could line up the cam time mark with advance triangle, time dot, or retard square. . I used the normal time dot. The only thing i can really think of it's that when i took off the old chain i lined up the two dots but don't remember looking to see where the chain was slack or tight.

In my fsm it shows you where to count the pins to make sure you have the chain in right. So i did that but i did use an edelbrock chain so it might be different..

Back to the distributor.
What you are saying about lining up the timing mark with tdc and checking the rotor to the #1 plug. I did do that when i put everything back together. But i didn't do it first off.. Lol i did say big learning curve



Spike

 

[mtnwhlr]

It sounds like you had it right but something changed after driving it that is why I was asking those ?s. Trying to think what could make it change.

 

[spikey]

I worked late tonight so reading up a little instead of working on it.
I'm really thinking that the best thing to do might be to just pull it all apart and see if the dots still line up.
It seems like a cam can go flat but usually if not broken I'm right. Buta flat spot on a cam can less to the timing jumping and backfiring. So if all else fails I'll check that out.

First things first though I'll be marking the parts inside the dist. To see if anything moves around.
It'll be another day driving the wives pp cruiser..

Spike

 

[tarry99]

Back to the distributor.
What you are saying about lining up the timing mark with tdc and checking the rotor to the #1 plug. I did do that when i put everything back together. But i didn't do it first off.. Lol i did say big learning curve



Spike

Motors are simple to diagnose once you understand the process and the order that each event takes place..............by referencing your timing marks it will make the job just that more simple.........
When you get a chance put it up on #1 TDC with all the plugs out and put a long breaker bar on the crankshaft nut and look at the piston while you slowly rotate the crank back and forth.............if for some reason that chain or gears are loose it will show up there...........the movements should be near 1:1............you never answered why the springs on the breaker plate were broken?
Also on your MSD box is there any timing controls built into it?

 

[spikey]

Umm not real sure why the springs broke. I've had plenty of people tell me they have never heard of that happening before. What i do know about it is that it was kinda the start of all this timing jumping thing. And that just clicked in my head just now...
I bought the jeep in march. I know it Sat for about two years. Well he drove it maybe once every other month. I got it and drive it daily. I changed a few hoses that had cracking but other than that it seemed fine.

Back to the springs. I took it on a camping trip that was 177 miles each way. On the way home about an hour away. Going up a long hill it started running real funny and didn't really sound too good. I pulled over checked fluids, let it cool down and babied it home. It was doing a diesling type thing when i would shut it off and was lurching at stop lights and such. So when i did the tune up i found both springs broken.

Sorry I'm bring long winded just trying to get all the info out.

But really after that is when it started jumping time. Oh yea one more clue was that it no longer had any extra oomph on the highway. Like if you let off the pedal and push it again you get the extra power to pass someone. That wasn't there anymore it just had what the pedal was giving you.

I mixed the springs in the dist because the spring kit came with a paper that showed different ways to tune and what different springs do. Then reading i think in the msd forums there was a thread about switching up the springs "using the chart" cause it will make little differences. So i figured it couldn't hurt.. Lol

Spike

 

[tarry99]

Umm not real sure why the springs broke. I've had plenty of people tell me they have never heard of that happening before. What i do know about it is that it was kinda the start of all this timing jumping thing. And that just clicked in my head just now...
I bought the jeep in march. I know it Sat for about two years. Well he drove it maybe once every other month. I got it and drive it daily. I changed a few hoses that had cracking but other than that it seemed fine.

Back to the springs. I took it on a camping trip that was 177 miles each way. On the way home about an hour away. Going up a long hill it started running real funny and didn't really sound too good. I pulled over checked fluids, let it cool down and babied it home. It was doing a diesling type thing when i would shut it off and was lurching at stop lights and such. So when i did the tune up i found both springs broken.

Sorry I'm bring long winded just trying to get all the info out.

But really after that is when it started jumping time. Oh yea one more clue was that it no longer had any extra oomph on the highway. Like if you let off the pedal and push it again you get the extra power to pass someone. That wasn't there anymore it just had what the pedal was giving you.

I mixed the springs in the dist because the spring kit came with a paper that showed different ways to tune and what different springs do. Then reading i think in the msd forums there was a thread about switching up the springs "using the chart" cause it will make little differences. So i figured it couldn't hurt.. Lol

Spike

Well like I mentioned before I would be looking at that breaker plate, everything your now saying points to a mechanical advance or retard issue. Does that distributor have a vacuum advance also? ( a pod on the side?)

Do what I stated before and get some timing reference points off the crank.........
It would be pretty hard to diagnose that distributors ability to work correctly over this computer..........
I would take the distributor out and call MSD.......... there in Texas and explain to them what its doing and what distributor you have and what springs you have installed........I'm sure they can walk you through there system to first see if all the parts are there and installed & functioning correctly.
Worth the phone call............there good people.

 

[Les]

Sorry to hear about all your timing issues, but they sound very familiar to an ongoing problem I had years ago with a Chevy engine, and it just about drove me nuts, before I found the problem. I too, thought my timing chain was jumping teeth, but it turned out to be something often overlooked and reasonably simple to fix.

What I found was that the lower bushing in my distributor was worn and out of tolerance, and that allowed the shaft to move enough laterally to jump a tooth or two between my distributor gear and the cam. When this happened, it would lose power, run very poorly, not want to shut off, and my strobe would later confirm that it had mysteriously gone several degrees out of time. I would re-time the engine and sure enough, before too long it would do it all over again. Before I found this problem, I had pulled the distributor several times looking for problems, but everything looked like it was operating normally.

I haven't had much experience working on the AMC 304 's, but I'm guessing there is at least a fair chance that either the bottom dist bushing is worn, or the dist shaft might have issues.....but most often, it's just the bushing.

Hope this helps with your problem...

 

[JR74CJ5]

What I found was that the lower bushing in my distributor was worn and out of tolerance, and that allowed the shaft to move enough laterally to jump a tooth or two between my distributor gear and the cam.

That may be your ticket. Diagnosis "should" be simple. Take th cap off the distributor, and see if the internals can lift enough to jump a tooth either way. The gears are not real deep between the dist and cam gear...

Good thought Les! It's a possibility I think...

 

[Les]

That may be your ticket. Diagnosis "should" be simple. Take th cap off the distributor, and see if the internals can lift enough to jump a tooth either way. The gears are not real deep between the dist and cam gear...

Good thought Les! It's a possibility I think...

In my case, the distributor managed to jump timing without any damage to the actual gear teeth, but all that extra movement caused strange things to happen up in the distributor head as well, and the fact that in this case, springs are mysteriously being damaged is what made me think of it. And if the distributor has previously been shimmed to adjust the gear mesh tolerances, then they might have got it just a bit high and even a small bit of wear would cause the dist to jump teeth.