Eightbanger

OK, firstly, be gentle as I know and understand nothing about auto electrics lol

For those that don't know I have recently redone the top end of my 303 which was starting an running before the work, now she's back together I try to start her and it just turns over, at no point did I remove the Distributor or move it, the leads are all new as are the plugs.
I have removed plug #1 and cranked the engine to see if I had spark and nothing, I have an Amp meter but am unsure as to how to use it other than sticking the Red terminal in various places lol with the ignition on and grounding the Black terminal to read 12V.
Today I removed the distributor cap cleaned the points and sprayed a bit of carb cleaner in there, now when I move the rotor arm by hand I get a spark with the ignition on (see vid), I also found a broken piece of what looks like thick pencil lead laying in there??? (see pic) then I cranked the engine to see what was going on with the rotor arm and can't see any spark or the points opening (see vid)....I'm lost.

m371961

Look on the inside of your dist. cap in the center. There should be a post that connects to the rotor when the cap is installed. My guess is that post is missing and is the carbon "pencil lead" you found.

MDchanic

Very likely - there is an imprint in the top of the center of the rotor electrode that looks to be the same size.



There's your problem, mate: Your rotor isn't turning.

Somehow you have disconnected your distributor from your engine.

What did you have apart and how did you put it back together?

I am not familiar with this block, but usually the distributor is driven off of the back of the camshaft - did you have the cam out?

You may need to pull the distributor and see whether the drive gear has fallen off the bottom.

- Eric

Eightbanger

Cheers Patrick, that's answered that, i'll need to buy a new cap then?

Unbelievable Eric, this is the kinda thing that bugs me, never messed with the camshaft, and the reason the distributor wasn't touched when I removed everything else was, in short...I couldn't get it out, it's seized in there solid, I undid the clamp but it wouldn't budge, so I thought leave well alone.

Two shots of the cam and base of the Dist, during cleaning and after during reassembly....nothing changed.

redoldsman

Did you pull the cap and wires off when you had the heads off?

Eightbanger

I think I may have done Red, I definitely did remove the cap at one point out of curiosity, can't be sure at which stage though, would that have caused the problem?

MDchanic

No, that would not have caused this problem.

- Eric

Ozzie

Eric's diagnosis is correct. Unless the rotor turns, it will not run. You appear to have spark at the points which probably means that the primary side of the ignition is O.K. (That sparking at the points may be a bit more than I usually get; it may be time for a new condenser.) Obviously the crankshaft is turning. There are only a few possible problem areas. You will probably need to remove the distributor. It is best to get it free anyway so you can check/adjust the ignition timing. It is probably stuck because it may have never been moved. I once had that situation on an old Ford engine. I finally got it out buy using two bolts with coupling nuts between the bottom of the distributor and the top of the manifold to "press it out". If you do this, do it uniformly so as not to crack the distributor. Inspect & clean the distributor. The distributor is driven by a gear on its shaft from another gear on the camshaft. It's also possible that the chain between the crankshaft and camshaft at the front of the engine could have failed. If this happens the valves will not operate. If the valves are operating the problem will be at the rear of the engine with the distributor or its coupling with the camshaft. Please keep us updated.

MDchanic

We're ASSuming that the camshaft is turning...

- Eric

Eightbanger

Just ran outside to check when I read this Ozzie, because I had the timing chain cover off as well but didn't remove the chain...did have a good clean round it though.

Boom!

Eightbanger

I can't believe it Eric..

Ozzie

When none of the valves are moving the problem is either with the chain drive between the crankshaft and camshaft or the camshaft is broken near the front.

MDchanic

... Or someone didn't screw the gears back on.

- Eric

Eightbanger

I wish the weather was better, I want to pull the front off and see what the heck has happened in there when that whole area was never messed with, save for a good clean of the chain while in situ with carb cleaner.

MDchanic

Well there's no nut on the end of the camshaft.

And, did you remove the key from the crank at any point?

- Eric

Eightbanger

Should there be a nut? that's how I found it, when the cover came off, I just snapped a pic.

By key, do you mean the one that the pulley slides over? if so, no not at all.

Ozzie

Your photography is good. There is a bit more corrosion than I am used to seeing there. There is no nut on that engine on the front of the camshaft. The three bolts holds the gear to the camshaft. The BT-11 alignment tool fits over the center snout. Those gears usually don't fail. The "funky" cam gears came on newer engines. The nicest thing would be if the chain broke. Expect to, as a minimum, buy a new chain. That one appears to be "slack" even if it didn't break. Once you get it all off, you can clean it up properly. Try to keep the crud from falling in the engine.

Ozzie

There is a key/keyway between the crankshaft & its gear. Perhaps this is what Eric meant. Usually it doesn't fail during normal operation. You can see it behind the slinger.

Eightbanger

Ok my buddies, who wants a good laugh..? your gonna love this update.

So the reason for the cam shaft not turning was indeed a broken timing chain, but it only broke because I fitted the fuel pump to the cover prior to installing the cover, which meant that when I installed the front cover the pump arm did not sit under the eccentric as it should, but instead got squashed between the inside of the cover and the face of the eccentric....so I crank the engine the fuel pump arm breaks falls into the lower sprocket and breaks the chain...viola!!

MDchanic

Ah, live and learn.

We've all done something like that once (or twice...).

Now you need a fuel pump, though, or perhaps just an arm.

Unless you've got a mate who can weld that up, which shouldn't be too difficult.

Mystery solved, and you'll have it sorted soon.

- Eric

oldcutlass

Oops

Eightbanger

I know, the list is growing Eric, Fuel Pump or arm (I had just rebuilt it too) Timing Chain and Distributor Cap as that carbon thing had broken off.

Ozzie

Such things can happen in the pursuit of our hobby. We are all learning from your experiences. You should be thrilled that it was only the chain and not the cam. This should be a relatively easy "fix" and it provided an excuse to get the rest of the area cleaned completely. That arm can be replaced on the pump if you've got an old one lying around the shop. If not, you can shop for a "core" on eBay to get the arm, or get a new or rebuilt pump while you're also shopping for a replacement chain. Thanks for providing us with additional knowledge and great photography.

Eightbanger

And thank you too Ozzie for all the help and info you've already given me...

Eightbanger

Guys, should I get just the Timing chain or a Timing chain set?

MDchanic

If I recall, this is a fairly low mileage car, plus these are steel gears, and they really do appear to have very little wear on them, so you will probably be fine if you just replace the chain.





That being said, it is always recommended to change the whole set, and usually does not cost much more. Also, I would look at the sprockets very carefully to be sure they were not damaged in the process.

If you are considering replacing the sprockets, be certain to purchase top quality parts - anything made in China is likely to be of lower quality than the used part you already have.

- Eric

Ozzie

I agree with Eric. You can do the chain only if you get a match for the original. The sprockets and chain should match on the sets. And it would be best to avoid the Chinese products. Their quality on auto parts seems to be somewhat worse than their quality on some other things.

m371961

I have done much worse in my time. Thanks for having the courage to admit yours.
I think if I could find good quality replacements I would replace chain and gears. They all wear together and fit into each other. But I have no idea if good sets are available.
Hang the chain on your wall.

Eightbanger

Ordered a Cloyes timing chain from Rock Auto...

Many thanks for the help and words of encouragement guys.

MDchanic

Just doin' our job...

- Eric

Rocketowner

Hey Nigel, I just spurred you along to do the TreadleVac rebuild, I didn't tell you that you could rebuild the whole Oldsmobile yourself, but if you believe, and think you can ,go right ahead. You Have certainly gained confidence in yourself , and I congratulate you. "Those who do no wrong , do nothing them self". Keep up the good work, Larry