My 440 died yesterday, and I would like to avoid throwing parts at it

-
Bill Crowell

Bill Crowell

Well-Known Member
Joined
Oct 16, 2007
Messages
1,170
Reaction score
803
Location
Diamond Springs, CA
Crank but no start. It sure sounds like the timing is off when I crank it. It backfires through the carb and kicks back on the starter when I squirt starting fluid into the ThermoQuad. Without the starting fluid it will hardly fire at all.

I've got 6.9 volts on the primary of the coil with the ignition in the "run" position. Is this adequate?

I tested the ballast resistor, and it was OK. I'm getting battery voltage at both ends of the "run" side of the ballast, and the "start" side does show continuity.

I do get spark at the plugs when I use a neon bulb tester, but it's not as bright as I think it should be.

It's a '78 lo-compression engine with the original timing set. To determine whether the timing chain or gear has gone bad, I propose to set the crankshaft to fire #1 and then see where the distributor rotor is pointed. It seems to me that I am going to have to pull the driver's side valve cover in order to make sure the engine is on its firing stroke, but I'd like to avoid tearing the engine apart as much as possible and, of course, firing the parts cannon.

My question at this time is: do I need to pull the driver's side valve cover, or is there an easier way to determine that #1 is on its firing stroke?

Also, would you have any troubleshooting suggestions?

Thanks a lot.
 
Pull spark plug,roll engine over with a socket on crank,finger over hole. As it reaches compression stroke you will feel it.
As piston is coming up, the timing mark will approach zero degrees.
Dont know if it is a dual pickup distributor,as in a lean burn system,very few have survived this long. Ignition controls can do this also.
 
All you need to do is pull the number 1 plug. With the engine cold and the coil wire off have someone bump the starter with you holding your thumb in the plug hole on the head. You'll get pressure when it's coming up on the compression stroke if you don't bump too fast. Once you feel the pressure on your thumb you can manually advance the crank to get it on TDC (timing mark). Then you can check the position of the rotor. It's really pretty easy, if you go past TDC just keep bumping until you get to the next compression stroke.
 
My question would be, what caused the timing to "go off"? If you were driving it, and it just died, how do you explain it? One possibility is that you slipped the timing chain. To determine this, I think you need a more accurate determination of TDC than the thumb method. Go ahead and pull the valve cover. Turn the crank over to get the timing mark at zero. Observe the valve positions on #1 (you may have to go around twice). One tooth on the chain isn't that many degrees, but it's valve timing, not ignition timing (although the distributor is driven off the cam, as well, so it will be off by the same amount, but it's the fact that the valves are mis-timed to the crank that is the real problem — you could always adjust the distributor).
 
mvh said:
My question would be, what caused the timing to "go off"? If you were driving it, and it just died, how do you explain it? One possibility is that you slipped the timing chain. To determine this, I think you need a more accurate determination of TDC than the thumb method. Go ahead and pull the valve cover. Turn the crank over to get the timing mark at zero. Observe the valve positions on #1 (you may have to go around twice). One tooth on the chain isn't that many degrees, but it's valve timing, not ignition timing (although the distributor is driven off the cam, as well, so it will be off by the same amount, but it's the fact that the valves are mis-timed to the crank that is the real problem — you could always adjust the distributor).
Click to expand...
The purpose of the "thumb" method is to determine if the distributor is in the correct relation to the crank timing mark. If you can get the car on the compression stroke on number one piston you can then manually move the to TDC. If the rotor isn't pointed to number 1 cylinder then the chain has slipped.
 
Are we to assume this happened suddenly??
check your rotor to make sure it's not broken. it's easy enough to bump the cap and break the rotor when the distributor is right out in front like that. Cap could be crusty too.
 
6.9v, how much you think will be left over when cranking?
Run a 12v wire from the battery to the + side of the coil. Then try and crank once more.

A weak spark can cause misfires.
 
If it has never been apart, the nylon ring may have deteriorated and left the chain to run on the bare aluminum sprocket. Happened to mine. The gear was bare and looked like a circular saw blade when I took it off. Similar symptoms to yours
 
TheGrateRonzini said:
If it has never been apart, the nylon ring may have deteriorated and left the chain to run on the bare aluminum sprocket. Happened to mine. The gear was bare and looked like a circular saw blade when I took it off. Similar symptoms to yours
Click to expand...

YUP ! that too
 
Pull the distributor cap and manually spin the engine one way and then the other. If it takes a while for the rotor to move again in the opposite direction the chain is done.
 
Jim Lusk said:
Pull the distributor cap and manually spin the engine one way and then the other. If it takes a while for the rotor to move again in the opposite direction the chain is done.
Click to expand...

This would be my very first move.
BTW, I push a piece of paper towel into the spark plug hole nice and tight and lightly bump the engine over until the paper pops out, then hand turn a bit more until the TDC mark comes up.
This makes it easily a one person job.
 
and again I warn people about shooting flammables into an open thermoquad. those things like to spit raw fuel and flame when they backfire.
firebog , I lost a 74 new yorker
 
I'm not the sharpest tool in the shed, but how old are the plug wires? I had some go bad on me, car didn't want to start.

How do the plugs look?

How messed up are the points?

The easy-to-check stuff can be easily overlooked.
 
you can use a screwdriver on the starter relay to bump the engine over. Since it's a 78, I assume it is an electronic dist.
Sometimes if the chain and gears are bad, you can actually see the rotor, not turning smoothly while cranking.
 
I agree the backfiring sounds like timing, but you say without starting fluid it hardly tries to fire... is it getting fuel?
 
Thanks, everybody, for your kind and thoughtful suggestions, which are really helping me narrow down the cause.

rustycowll69 wrote: "Sometimes if the chain and gears are bad, you can actually see the rotor, not turning smoothly while cranking."

I really like that suggestion, rustycowll69, and I am going to try that first because I can watch it easily right under the hood, with a starter button across the starter solenoid.

I also like BigBlockMopar's suggestion that I check the coil primary voltage in the ignition "start" position, and compare that to the voltage I get with the primary connected directly to the battery.

And Bulldozer, you got me thinking about how dangerous it is to crank a carbureted engine when a plug might fire while the intake valve is open because the timing is off. Thanks for that.

Also, concerning the coil primary voltage issue, that 6.9 volts is in the ignition "run" position, not "start", so it might be OK. I am going to check it, though, by removing the positive wire from the coil primary and seeing how much voltage it has when floating; then measure the resistance of the coil primary; then calculate with Ohm's law how much voltage drop the coil primary by itself should create, and if I have more voltage drop than that, I will know that I have additional resistance somewhere in the ignition circuit.

I will report back! Thanks again. If I do have to pull the front cover off the 440, I'll be sure to post pictures of the original timing gear and chain before I remove them.
 
Last edited:
TheGrateRonzini said:
If it has never been apart, the nylon ring may have deteriorated and left the chain to run on the bare aluminum sprocket. Happened to mine. The gear was bare and looked like a circular saw blade when I took it off. Similar symptoms to yours
Click to expand...
hopefully the cam sprocket doesn't look like a circular saw blade, hahaha.
I've never done it on a B engine, but you might be able to remove the fuel pump and fuel pump pushrod and snake a borescope in and take a peek.
If it does look like a circular saw blade, all that plastic wiIl end up in the sump, and you'll have to pull the pan and pickup to clean all that debris out.
 
I was able to verify that the problem was the timing gear and chain by rocking the crankshaft back and forth. There was a lot of lost motion in the distributor shaft.

I am going to clean up the front of the engine before pulling the front cover. When I do pull it, I'll take pictures of the 40-y.o. timing gear and chain and share them with you.

It was pretty hard to get the harmonic balancer to break loose, but I finally did. However, I the pulleys don't want to come off of the balancer easily, and I don't want to bend them.

How do you separate the pulleys from the harmonic balancer on a 440?

Let me know if you need to see pictures of the pulleys and balancer.

Thanks again for all the advice, FABO!
 
Here's the timing gear and chain. When the dot on the crankshaft is at 12 o'clock, the mark on the cam gear is at about 7 o'clock. It looks like it has skipped one tooth.

The teeth on the cam gear are almost gone in spots.

timing gear.jpg
 
Looks like you have some chain set replacement work to do. What's more your oil pump pickup will likely have some of that plastic in it.
 
looks like it's a good time to pull/clean the pan, and pickup. When you shake the pickup, it'll sound like a maracas. There may be umbrella valve stem seal pieces in there, too. Now is an opportune time to match mark the inner hub/ outer ring of dampener, so that you can tell if the outer ring slips in the future.
 
The worst I've ever seen was on my dad's '69 Fury (383 two barrel). The chain and sprocket were so bad the chain slipped off without removing the cam sprocket. A couple of weeks prior I had driven that car about 300 miles on a church trip, then it broke on my brother as he was arriving at work one morning. In the case of a '69 383 it is an interference engine...it was a mess that we never did get fully right again as dad didn't want to do the heads and I was likely incapable of getting them out at that time. I was in a back brace recovering from a broken back, but I did the rest of the work...
 
This old 440 in my D-300 Adventurer SE has been back together for some time now with a new timing set, and is running like a champ! It's a '78 model, and the heads have never been removed.
 
Bill Crowell said:
This old 440 in my D-300 Adventurer SE has been back together for some time now with a new timing set, and is running like a champ! It's a '78 model, and the heads have never been removed.
Click to expand...
What made you decide to remove the timing cover??? Or did you just do it because that's what you suspected??
 
You must log in or register to reply here.
-

Back
Top