Strange Timing

485 Views 18 Replies 12 Participants Last post by MustangGrande302, 11 d ago

damurray1243

Discussion Starter · 12 d ago

I have a 289 that the timing is weird on the timing mark on the balancer is at the 12:00 position I have a video of it with a timing light and when I move the mark with the distributor the closer it gets to the other mark the worse it runs and when it gets to it it dies instantly when I put it at the mark to mark by hand I put the distributor in correctly but what could cause it to not be exactly timed when running

1 - 19 of 19 Posts

OneTireFire

· #2 · 12 d ago

Either the distributor is a tooth off or the mark is at TDC, which is 0 degrees and the ignition needs to happen before that.

damurray1243

Discussion Starter · #3 · 12 d ago

Th

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damurray1243

Discussion Starter · #4 · 12 d ago

That is where it is when running

AZ_Ryan

· #5 · 12 d ago

I don't fully understand the question. Some punctuation might help clarify.

Reactions: 3

HPjunki

· #6 · 12 d ago

At what rpm? With vac capped? All in with vac and 3k pm?
Troy

damurray1243

Discussion Starter · #7 · 12 d ago

AZ_Ryan said:
I don't fully understand the question. Some punctuation might help clarify.

Basically the timing mark on the balancer is at the 12:00 position and if i move it to the mark on the cover it dies but where I have it now runs the best but has a slight miss

AZ_Ryan

· #8 · 12 d ago

damurray1243 said:
Basically the timing mark on the balancer is at the 12:00 position and if i move it to the mark on the cover it dies but where I have it now runs the best but has a slight miss

Well chances are strong your timing marks are off then. You need to find TDC and verify.

Reactions: 1

my289

· #9 · 12 d ago

That looks like maybe 40deg BTDC. It seems your distributor is plugged into full vacuum? You have to disconnect the vacuum when setting timing.

Reactions: 1

C-Woods-70

· #10 · 12 d ago

If your vacuum advance is connected to ported vacuum, nothing will change when disconnecting it unless your idle is set too high.
If engine gets worse and dies as you adjust the 10 degree mark (white line) towards the timing pointer, then the harmonic balancer must be wrong or has deteriorated and slipped. I don't think that any small block ford timing pointer is at 12 o'clock, but it sounds like this is where your engine wants to run, so it has to be close.
The 9 washers behind the timing cover/water pump bolt tells us that there may be a mismatch of parts also.

Grimbrand

· #11 · 12 d ago

It's also very common for dampers to fail. When the elastomer becomes old and brittle, the weight ring can slip on the hub. So now "TDC" doesn't match "TDC" anymore, and worse, the weight is no longer balancing the crank, because it's off to one side or the other. Additionally because the elastomer is not damping vibration properly, your crankshaft is whipping back and forth like the big steel spring that it is, trashing bearings and possibly breaking things.

If it's not the original damper, often the pointer is not accurate in the first place; the marks may not match up with your engine's pointer location.

So use a piston stop, or whatever method you prefer to make sure the piston is really at TDC, and verify that the pointer is pointing to "0"' when it's there.

Remember: for verifying your timing mark, it doesn't matter whether you are on compression or exhaust - "0" on the crank is still zero. When you put in your distributor, you need to know whether it's zero, AND on the compression stroke so you can be sure your bug is pointing to the #1 spark plug wire.

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Reactions: 1

W427

· #12 · 12 d ago

You are getting good advice. But to know what is causing the issue, you need to verify TDC of #1 cylinder with a spark plug thread piston stop. About $10 online if you shop around, or make your own from an old spark plug and a bolt. This tool will show exactly where TDC is, and if your damper ring has slipped, or your distributor is off a tooth, or the plug wires are off a terminal, or using the wrong timing pointer or damper, etc.

damurray1243 said:
I put the distributor in correctly

Otherwise tell us exactly how you did this. You may have done it perfectly, but then we are back to testing TDC with the tool...

I suggest you use the tool, or an equivalent method.

Reactions: 1

66_72stanger

· #13 · 12 d ago

C-Woods-70 said:
If your vacuum advance is connected to ported vacuum, nothing will change when disconnecting it unless your idle is set too high.
If engine gets worse and dies as you adjust the 10 degree mark (white line) towards the timing pointer, then the harmonic balancer must be wrong or has deteriorated and slipped. I don't think that any small block ford timing pointer is at 12 o'clock, but it sounds like this is where your engine wants to run, so it has to be close.
The 9 washers behind the timing cover/water pump bolt tells us that there may be a mismatch of parts also.

C,

well done!
qquite the eagle eye.

BlackStick

· #14 · 12 d ago

"...closer it gets to the other mark..."

Are you talking about the pointer? Or are you talking about that other surface painted white that is lined up with 10 deg in your photo?

Woodchuck

· #15 · 11 d ago

OneTireFire said:
Either the distributor is a tooth off or the mark is at TDC, which is 0 degrees and the ignition needs to happen before that.

The distributor being "off a tooth" or wires not in the "correct" location on the cap do not affect timing, unless the distributor housing has not been turned to compensate and then the engine will run like crap.

Reactions: 2

MustangGrande302

· #16 · 11 d ago

W427 said:
You are getting good advice. But to know what is causing the issue, you need to verify TDC of #1 cylinder with a spark plug thread piston stop. About $10 online if you shop around, or make your own from an old spark plug and a bolt. This tool will show exactly where TDC is, and if your damper ring has slipped, or your distributor is off a tooth, or the plug wires are off a terminal, or using the wrong timing pointer or damper, etc.
Otherwise tell us exactly how you did this. You may have done it perfectly, but then we are back to testing TDC with the tool... I suggest you use the tool, or an equivalent method.

Another way I was taught to do this was in an engine overhaul class last year. You can stick a long screwdriver into the spark plug hole to verify TDC.

OneTireFire

· #17 · 11 d ago

Woodchuck said:
The distributor being "off a tooth" or wires not in the "correct" location on the cap do not affect timing, unless the distributor housing has not been turned to compensate and then the engine will run like crap.

👍🏻

Woodchuck

· #18 · 11 d ago

MustangGrande302 said:
Another way I was taught to do this was in an engine overhaul class last year. You can stick a long screwdriver into the spark plug hole to verify TDC.

No, you can't. You can tell when the piston is in the VICINITY of TDC, but since the crankshaft rotates in a circle the piston "dwells" near TDC over a number of degrees which you really can't perceive with a screwdriver to accurately mark a timing scale.

From the point when the crank throw is at 90* upward, the piston speed slows considerably to zero at exactly TDC. Depending on the stroke and the length of the connecting rod, the piston may be near stopped from a number of degrees before and after exact TDC. This is why, when you use a "piston stop" to determine TDC you rotate the engine back and forward against the stop and select the point exactly in between.

Reactions: 4

MustangGrande302

· #19 · 11 d ago

Woodchuck said:
No, you can't. You can tell when the piston is in the VICINITY of TDC, but since the crankshaft rotates in a circle the piston "dwells" near TDC over a number of degrees which you really can't perceive with a screwdriver to accurately mark a timing scale.

From the point when the crank throw is at 90* upward, the piston speed slows considerably to zero at exactly TDC. Depending on the stroke and the length of the connecting rod, the piston may be near stopped from a number of degrees before and after exact TDC. This is why, when you use a "piston stop" to determine TDC you rotate the engine back and forward against the stop and select the point exactly in between.

The piston stop seems better than a screwdriver. Thanks for the explanation!

Reactions: 2

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