help

[bhiland]

So the wife and I took a drive today in the A and had some trouble. Everything was fine and we had drove several miles. Came to a stop sign and when we took off again we lost power. I looked at ignition switch and the key was turned back just enough to kill it I guess. It has happened before. So I turned they key back on and was fine for a few seconds then BANG backfire! Then crazy engine knock and no power so I killed it and brought it to a stop. Looked all over the engine and didn't see anything out of norm. Let it sit for a few minutes and tried to start it again. It started and knocked for a few and then stopped knocking but have less power and not much oil pressure. I limped it home and now deciding where to start.

[afuncar]

I think you should take a look at dist and timing after that I,d look at timing gear possable oil pump and dist. Drive gear. Good luck

[1crosscut]

Probably when the switch turned off you built up unburnt fuel in the muffler causing the back fire. May be possible that you collasped a baffle or two in the muffler and it's causing back pressure and loss of power. Going to be loud but pull the muffler loose from the manifold and see if you gain back your power.

A's don't have very much oil pressure to start with. Mostly they flow a lot of oil with very little pressure. As long as your registering a couple lbs. or so your probably good.

[Purdy Swoft]

I would remove the side timing cover, turn the engine over with the starter , with the spark plugs removed. Watch the teeth on the timing gear when it turns. I figure that some teeth will be damaged and missing.. There are two 5/8 bolts on the side and one under the edge of the oil pan, that a 1/2 inch socket will fit. If you are careful the side timing cover can be removed without damage to the oil pan gasket. When the timing gear starts to fail, it will buck and knock and won't run good at all. The cam turns the oil pump, if the cam gear is striping and skiping the oil pump can't function at an optimum level.

[bhiland]

Ok ill check all of that also. My coil doesn't have much power now either when I use the tester.

[bhiland]

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Well I have no compression on #3

[Tom Wesenberg]

With timing pin in the cam gear dimple, is the rotor pointing at #1 and just ready to open the points? CCW rotation

[glenn in camino]

Start by telling your wife that you're sorry, your Model A is sorry and she doesn't have to go on the next ride, unless she wants to. You'll find out how much she loves you. My wife and I have been riding in our Model As since the late 60s. She always takes a good book and now her favorite Model A tool, her cell phone.

[bhiland]

Yes its at #1 but I think the points may be a little bit before just opening

[bhiland]

Originally Posted by glenn in camino

Start by telling your wife that you're sorry, your Model A is sorry and she doesn't have to go on the next ride, unless she wants to. You'll find out how much she loves you. My wife and I have been riding in our Model As since the late 60s. She always takes a good book and now her favorite Model A tool, her cell phone.

She loves the car and all ready said sorry to all involved lol.

[bhiland]

I'm wondering if it dropped a valve.

[Tom Wesenberg]

Originally Posted by bhiland

I'm wondering if it dropped a valve.

Crank the engine so the bad cylinder piston is TDC on firing, then blow compressed air into the spark plug hole. If it has 0 compression, the air will come out the carb (intake valve), or tail pipe (exhaust valve), or oil fill pipe (bad rings or piston).

[Will N]

So your problems all started from a backfire due to a bad ignition switch? Whenever someone in our club has problems with their ignintion switch, the first thing we look at is how many keys do they have hanging on their keychain. All that extra weight pulling on those repop switches, which usually do not have a strong detente on either the on or off positions, is the first culprit that we find causing the intermittant switch problems.

[Mike V. Florida]

Double check the ign switch for reliable operation. An intermittent switch will show all the symptoms you describe.

[bhiland]

Piston is moving couldn't get a good look at valves. Piston looks wet and looks like it has some scaring on the head of piston.

[bhiland]

Originally Posted by Will N

So your problems all started from a backfire due to a bad ignition switch? Whenever someone in our club has problems with their ignintion switch, the first thing we look at is how many keys do they have hanging on their keychain. All that extra weight pulling on those repop switches, which usually do not have a strong detente on either the on or off positions, is the first culprit that we find causing the intermittant switch problems.

Only got ignition key and key for side mount lock on the key ring.

[bhiland]

Originally Posted by Mike V. Florida

Double check the ign switch for reliable operation. An intermittent switch will show all the symptoms you describe.

But I have hardly any oil pressure and it was knocking to beat the band for a minute. Ignition switch wouldn't cause that and no compression in #3 cylinder.

[Purdy Swoft]

You may have a combination of problems. I had a lot of problems with the low cost ignition switches. The only reason that I didn't mention the switch in post number 4 was because you mention knocks and loss of oil pressure in the original post. You've got a strange combination of symptoms!!

[Mike V. Florida]

Please describe your engine, Stock or what? Stock engine only has two or three pounds when warmed up.

[bhiland]

Its just a stock engine with stock head.

[bhiland]

Like gouges but cant tell. Got a fellow A'r coming tomorrow. And going to bring a little scope cam to see down in it and get a plan of attack.

[Purdy Swoft]

You really need to remove the valve cover to check the valves. You can tell if the valve is stuck open on the number three cylinder. With the spark plugs removed the engine will be easy to turn with the hand crank or the starter. With a helper turning the engine watch the lifters where they meet the valve stims on the number three. If a valve is stuck open you will see that one of the valve springs won't be moving. I would be positive that a valve was stuck in the up position before pushing on it with anything. If you don't want to lose any oil, you can drain the oil pan first and if you don't want to change it you can replace it..

My first guess for loss or sudden loss of compression would be a stuck valve. With ethanol fuel, it can happen pretty quick, its happened to me. Still doesn't explain knocking and loss of oil pressure.

[sidhartha]

Originally Posted by 1930 coupe

This is way out in left field and very remote.
What if a small rock or something bounced up from the tire and got sucked in the carb and made it to #3 cylinder. Could make a knock, scar up the piston and hold the valve open.

It might be possible, but I'm pretty sure he is running an air maze.

[Purdy Swoft]

It could do all of that if a rock was in the cylinder. The engine wouldn't have enough vacume to draw a rock through the carburetor ,up the manifold and enter the combustion chamber.

[James Rogers]

Blown head gasket.

[BILL WILLIAMSON]

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One guy lost a carb jet tube & it sucked it in & it stuck under a valve. Bill W. (Just pop off the carb bowl & see if a jet tube is missing)

[bhiland]

Well we took a look with the camera and didn't see much so going to pull the head and take a look. Leaning toward a bad exhaust valve.

[Mitch//pa]

I would do suggestion # 12 before removing the head. A leak down test is a valuable diagnostic step

[bhiland]

Originally Posted by Mitch//pa

I would do suggestion # 12 before removing the head. A leak down test is a valuable diagnostic step

Wouldn't that be hard yo tell with the manifolds still in though?

[Mitch//pa]

Originally Posted by bhiland

Wouldn't that be hard yo tell with the manifolds still in though?

A leak down test is to determine where you are losing compression. The manifolds being on will not affect the test

[bhiland]

Ok I will do that and see what happens.

[Mitch//pa]

Good move report results
Also take off the radiator cap and make sure no air is coming up through the cooling system along with checking at the carb throttle plate open and tailpipe, // crankcase oil fill...

[BILL WILLIAMSON]

IF you have hard valve seats, possibly lost one??? Bill W.

[bhiland]

Originally Posted by BILL WILLIAMSON

IF you have hard valve seats, possibly lost one??? Bill W.

Yep I did. I did the air testband had air from exhaust manifold. I took the head off and the valve seat is gone.

[bhiland]

So now what? Need to make a plan. What should I replace?

[700rpm]

Good call, Bill. But how can you lose a valve seat? It's smaller than the head of a valve, so it wouldn't come off and over the valve, and too large to get into the block. Wouldn't it just rattle around in place? Am I misunderstanding something?

[BILL WILLIAMSON]

Originally Posted by bhiland

So now what? Need to make a plan. What should I replace?

Well, my Friend, I would suggest you take off the manifolds & the side valve chamber cover & pay a good AUTOMOTIVE machinest to come by & evaluate your situation & map out a PLAN. Bill W.

[bhiland]

I was hoping it would be something easier than that but guess not.

[bhiland]

Originally Posted by 700rpm

Good call, Bill. But how can you lose a valve seat? It's smaller than the head of a valve, so it wouldn't come off and over the valve, and too large to get into the block. Wouldn't it just rattle around in place? Am I misunderstanding something?

I'm guessing it shattered. The seat is gone and there was no pieces anywhere.

[BILL WILLIAMSON]

Originally Posted by bhiland

I'm guessing it shattered. The seat is gone and there was no pieces anywhere.

I would imagine that a complete loose seat could hang out over the bore & be clobbered by the piston & the pieces passed out the exhaust valve & are probably rattling happily in the muffelator. Possibly piston damage, also. Bill W.

[James Rogers]

Sounds like someone put in a cast iron seat and it worked loose. Once it came loose it was beat to pieces and expelled through the exhaust port into the muffler. If you remove the exhaust, you will find pieces in the muffler.

[bhiland]

Yes I believe they are cast iron. Ive had the car for 4 years but don't know much about restore. My wife's uncle had the car and gave it to us before his passing. I don't believe the engine has been touched for many years. They gave it a new paint job and put it back at restore from the evidence.

[James Rogers]

Try to find someone who has a Kwik-Way or K O Lee portable seat tool and have a new seat installed by someone who knows what they are doing. These can be used in the car and work great.