strange timing issue

[killnine]

So I finally got a piston stop tool and spent some time today verifying TDC, since I've never been 100% sure. I rotated it around both ways, marked things, found the middle, and it was where TDC was marked on the balancer. I made sure this matched with the valves being closed and the rockers loose.

Here's the problem. If I put the rotor in pointing to #1 at this point, it will barely try to fire, and will be way too retarded. Even if I adjust it to where the distributor is able to be advanced as far as it will go, it's still not enough. I have to take the distributor out, move the rotor one tooth advanced, and put it back in. Then, I can start it, etc. The timing light at this point will show it at about 12 degrees or so advanced, and that or a little more is where I leave it and it runs fine.

So of course at this point the rotor at TDC is basically almost pointing to the #4 or whatever next plug is in the cap.

My worry is that this is a sign of something that needs to be resolved otherwise. Like a cam timing issue or something.

I would not be surprised if the PO did something weird when installing the cam/chain/gears. He also had the firing order one forward on the distributor cap to resolve this issue. That would be another way to deal with it, but it's obviously still a problem.

 

[JoeSBP]

Reluctor upside down?

 

[slantsixdan]

There is a second bolt under the distributor. It holds the hold-down plate to the distributor body. Use the correct wrench to loosen this bolt with the distributor installed, or remove the distributor and use a regular wrench. Move the plate relative to the distributor to get the additional movement you need to include a range of about 2° BTDC to 12° BTDC within the hold down plate's slot where it attaches to the block.

As for your rotor-to-cap phasing: the distributor might have been installed incorrectly (governor cam installed backwards, distributor drive pinion improperly phased). If your timing mark is at verified-TDC with both frontmost valves closed, your cam timing probably isn't off by far, if at all.

 

[AJ/FormS]

If your timing mark is at verified-TDC with both frontmost valves closed, your cam timing probably isn't off by far, if at all.

Exactly correct.
If after going through the above ritual, it still looks odd, rev the engine up a bit and watch the timing mark; it should smoothly march ahead with absolutely no funny-business. If it gets to dropping sparks or retarding or jumping all over the place in a totally random manner, I have seen this when the pick-up polarity has been reversed. My cure happened to be in a tool-box drawer, a reverse-polarity factory jumper.If you see this monkey-motion just cut the pick-up wire,reverse the leads, solder and shrink-tube and you are done. Not so fast. You will have to retime your ignition and then rephase your distributor body, to put the rotor back under the correct tower.Then you will have to verify the timing one more time. Easy peasy right? Hopefully you won't need to do this.
Also make sure your vacuum advance can is working and that the advance plate is not hung up in the wrong place.

 

[killnine]

There is a second bolt under the distributor. It holds the hold-down plate to the distributor body. Use the correct wrench to loosen this bolt with the distributor installed, or remove the distributor and use a regular wrench. Move the plate relative to the distributor to get the additional movement you need to include a range of about 2° BTDC to 12° BTDC within the hold down plate's slot where it attaches to the block.

As for your rotor-to-cap phasing: the distributor might have been installed incorrectly (governor cam installed backwards, distributor drive pinion improperly phased). If your timing mark is at verified-TDC with both frontmost valves closed, your cam timing probably isn't off by far, if at all.

Hi Dan,

The bottom plate is already adjusted as far 'advanced' as it will go. This plus full rotation of the distributor to the left (until it hits the block) with the rotor pointing to #1 was the spot I started in, and was still too retarded. As it is now I have enough range to put it way too retarded and way too advanced, so it all seems 'right', except for the fact that it started out pointing at the next plug instead of #1. Glad to know the cam timing is probably correct. It is possible I put the distributor together wrong somehow. I did take it apart and cleaned it up and put it back together, so I could check what was in it. It runs great as it is, or at least it seems to run great to me. I'll take it out and go over it again.

 

[killnine]

Exactly correct.
If after going through the above ritual, it still looks odd, rev the engine up a bit and watch the timing mark; it should smoothly march ahead with absolutely no funny-business. If it gets to dropping sparks or retarding or jumping all over the place in a totally random manner, I have seen this when the pick-up polarity has been reversed. My cure happened to be in a tool-box drawer, a reverse-polarity factory jumper.If you see this monkey-motion just cut the pick-up wire,reverse the leads, solder and shrink-tube and you are done. Not so fast. You will have to retime your ignition and then rephase your distributor body, to put the rotor back under the correct tower.Then you will have to verify the timing one more time. Easy peasy right? Hopefully you won't need to do this.
Also make sure your vacuum advance can is working and that the advance plate is not hung up in the wrong place.

Thanks AJ, I'll check on that also.

 

[AJ/FormS]

Which tower is which, makes no never mind. As long as the rotor ends up close and the timing mechanisms do not cause a crossfire/missfire,you're good to go. Don't lose any sleep over exactly where the rotor is. On a slanty the factory coil can handle a lil extra rotor to tower gap, and in fact that extra spark-gap will make the coil work harder to deliver more to the plugs. I'd call that a win-win situation.

 

[killnine]

I switched the wires for the distributor around, and now (while it is pointing one plug advanced to get it to run), it is doing exactly what it did when it was pointed at #1 plug at TDC. Fails to start, but tries, like it is too retarded almost, or out of time. So this makes me thing maybe if I put it back to pointing to #1 at TDC, with the wires switched, maybe it will be back to normal. I'll try tomorrow.

 

[AJ/FormS]

It matters not a bit where you clock the dizzy driveshaft, when you put the light on it to reset the timing you will have to rotate the dizzy body back into the same relationship, to get the timing back. The problem with that is, that,you run out of room for the Vcan, or out of room on the adjustment slots.
The only ways to re-phase the rotor to get it under a tower, is to re-clock the reluctor, or to relocate the rotor tip,or to re-anchor the cap, or to alter the timing plate's parking position with the vcan arm.Then whatever tower the rotor ends up under,with the #1 piston between TDC and about 15* advanced, will be the new #1 wire,going to the #1 plug.
I figured this out very very early in my career, when I ran into a teener with a jumped timing chain. I had that dizzy in and out about 6 times,re-clocking that stupid oil-pump drive, and it made absolutely no difference, except the Vcan moved to a new location; and eventually it either ran out of room at the firewall, or it ran out of room hitting the coil. Since the car was in an unheated garage and it was in late December, this was a very frustrating experience for me. I was in my early 20s,22 maybe.

Going back to your first post, if it runs that way, does not crossfire and does not overadvance under power, then forget about where the rotor is. The rotor starts moving as soon as the timing changes, and will be in a new position with every degree change in timing,until the timing is all-in; then the rotor quits moving. The timing plate moves when the vacuum advance can starts doing it's thing, and stops when it's contribution is all in. There is a continual dance going on under that cap. If it doesn't fire to the wrong tower, which you will know the second it happens,all is good.