[Kenth]

I´m setting timing static with testlamp at 9°, starts engine runs ok, then checking dynamic timing with strobe and timing shows close to 30° BTDC.
Setting dynamic timing back to 9° engine runs like crap and stops.
No vacuum advance during settings.
What is going on here?
Thanks

[dataway]

Super weak springs on the advance weights?

What kind of ignition system? Points?

[67drake]

Which direction are you rotating engine to check static? Distributor gear lash?

[mchell]

Is this a test?

Bad balancer
Broken dist. advance mechanisms
Bad timing light

[Navy Horn 16]

If you can make the engine run, start with 12 degrees at idle. Go from there.

[Schurkey]

Originally Posted by dataway

Super weak springs on the advance weights?

What kind of ignition system? Points?

Originally Posted by 67drake

Which direction are you rotating [distributor] to check static? Distributor gear lash?

Originally Posted by mchell

Bad timing light
Broken dist. advance mechanisms

You guys covered everything I was going to ask. Particularly, the bold (above.) I put the timing pointer and damper mark where I want the advance to end up; then turn the distributor body the opposite direction to rotor movement (backwards) to get static timing.

Originally Posted by mchell

Bad balancer

Should show the same advance static or dynamic--unless it's so loose that it's actually moving around randomly; and I'm sure he'd notice that.

[shaker455]

Kenth, maybe test to see how much slack is in the timing chain.
Also make sure your advance is moving properly
Jeff

[ChiefCrazyCanuck]

If I understand your post correctly you are setting your dynamic timing which is at rpm back to 9 degrees? If so, that is why.

Your static was 9 degrees, and 30 total or dynamic. If you reduced your dynamic to 9, you just pulled 21 degrees out and it would be idling at about 12 degrees ATDC. Hence the issue if that is the case.

[Kenth]

Originally Posted by dataway

Super weak springs on the advance weights?

What kind of ignition system? Points?

1970 455 points distributor with original springs with good tension.
It has worked flawless for some years, but recently i was checking dwell and dynamic timing and found timing at nearly 30° w/o vacuum advance at idle speed. Setting dynamic timing back to 9° and no go.
Setting static i turn the damper to 9° on scale and turn the distributor CCW until the testlamp just lights up and then lock the distributor.
Strange thing is i can set static timing at 9°, start engine and for some unknown reason dynamic timing is back to 30°!
And, i have two different stroblamps showing the same.
No difference with old or new points set at 30° dwell, new condenser .204 Mfd.

Would it make a difference turning the distributor CW setting static?
May try that tomorrow.

[77 TRASHCAN]

Would it make a difference turning the distributor CW setting static?

Slack in timing chain

May try that tomorrow.[/QUOTE]

[Joe's Garage]

To set the static timing, position the engine at about 15* BTDC on the compression stroke on #1, using the timing scale on the timing cover. Verify that the rotor is sort of pointing at the terminal with the #1 plug wire attached to it.

Disconnect the spark plug wire from #1 at the spark plug and stick a phillips screwdriver into the wire. Hold the wire about 1/8" away from the valve cover or the head - wherever it is easy to hold onto the plastic grip while you turn the distributor.

Turn the distributor COUNTERCLOCKWISE about 1/2 the distance between two cylinder terminals. Turn the ignition key ON, or use a jumper to get power to the coil. Then, while holding the screwdriver by the handle (so you don't get shocked), slowly turn the distributor CLOCKWISE until the coil fires and you see a spark off the screwdriver shank to the engine (ground).

Repeat this a couple times until you get the distributor as close as you can to being exactly where the coil fires. Then tighten down the distributor hold-down. Re-verify the timing - sometimes it will change a little when you tighten the clamp. If it does, reset the timing to compensate for the change.

Now check your timing with the engine running and adjust as needed.

To check the timing chain for slack WITHOUT disassembly, put a big socket on the crank and turn it CLOCKWISE until the timing mark on the dampener is at '0' (TDC) on the timing cover.

Take off the distributor cap and secure it out-of-the-way, so that you can see the rotor clearly.

This 2nd part might require a 2nd set of eyes - depending on how hard it is to manipulate the ratchet or breaker bar on the crank AND watch the distributor rotor clearly.

Turn the crankshaft, very slowly, COUNTER-CLOCKWISE until the rotor just barely moves. Stop there and see where the timing mark lines up with your timing scale on the timing cover.

If it's at 4*, then you have 4* of slack in the chain. If it's at 12*, there is 12* of slack in the chain.

We've used this as a quick way to check for slop forever.

As far as checking the timing mark on the dampener to see if it has moved, that is a little more difficult to explain.

Good luck.

[Schurkey]

Originally Posted by Schurkey

I put the timing pointer and damper mark where I want the advance to end up; then turn the distributor body the opposite direction to rotor movement (backwards) to get static timing.

Originally Posted by Joe's Garage

Turn the distributor COUNTERCLOCKWISE about 1/2 the distance between two cylinder terminals. Turn the ignition key ON, or use a jumper to get power to the coil. Then, while holding the screwdriver by the handle (so you don't get shocked), slowly turn the distributor CLOCKWISE until the coil fires and you see a spark off the screwdriver shank to the engine (ground).

Originally Posted by Kenth

Setting static i turn the damper to 9° on scale and turn the distributor CCW until the testlamp just lights up and then lock the distributor...

...Would it make a difference turning the distributor CW setting static?

Absolutely. You're turning the distributor the wrong direction. Pontiac rotor spins CCW. Therefore, you need to turn the distributor body CW. As "Joe's Garage" said, turn the distributor "too far" counterclockwise, then watch for spark, or watch the test light as you turn it BACK, clockwise. When you get spark, or when the test light glows, (points just open) lock the distributor.

I havent done this with points for decades. This is why I like HEI--I just align the inner and outer teeth of the reluctor and pickup coil--which I can usually "feel" due to the magnetic attraction--and lock the distributor.

[Kenth]

Thanks all for your replies.
Mchell nailed it, bad balancer.
Totally unexpected but still.
The new CAT OEM replacement damper was mounted 2 years ago and now the outer ring has moved. What a POS!

[Tom Vaught]

I have seen several of the Chinese knock-offs move over the years.
That is why I use only ATI Super Damper Balancers.

No saying they might not have a bad one, but I have never purchased a bad one and they have made me a couple of custom Belt driven Vortech supercharger Dampers.

Glad you found your issue Kenth.

Tom V.