Distributor Installation Issues with Timing Mark on Harmonic Balancer

[jbanna]

Help!  I have removed and installed my distributor countless times, but this time I am stumped - I dropped the distributor in so the rotor is on the #1 cylinder and the piston was TDC; however, it won't start and backfires uncomfortably...when I checked the timing mark on the harmonic balancer, the mark is  almost 180 degrees off the scale on the timing chain cover.  The car was running ok before and there hasn't been any sounds indicating something is broken.  I've read there are two TDCs, but that doesn't make sense - I also had my wife feel the compression when the piston reached TDC (and of course I can see the top of the piston through the spark plug hole...any advice please?  Thanks, Joe

[b_hill_86]

Well, there are two TDCs. One on the end of the exhaust stroke and one on the compression stroke. We obviously want the compression stroke. Setting the distributor on the exhaust stroke TDC is referred to as 180 out but that should still set your balancer mark at zero. Is it possible your balancer spun (I believe technically called a damper in the case of pontiacs)

Why did you pull your distributor? Maybe a few pictures of things would help narrow down what’s going on.

You ought to be able to set #1 at TDC on the compression stroke, install the distributor with the rotor at the #1 cylinder wire and assuming the other wires are in order (are they?) it should fire off without even looking at the balancer.

[TA301]

Yes, why did you pull the distributor? What did you do to it?

[nUcLeArEnVoY]

I never do the "finger in the hole to feel compression" thing. It just doesn't work for me, I never really get a sense for how it's supposed to feel. My balancer is thankfully not spun and is actually accurate, so all I do to make sure I'm at TDC is stick a straightened out clothes hanger in the #1 spark plug hole and I'll turn the engine with a ratchet. Once the timing mark gets close to zero, I'll slow down and carefully watch the clothes hanger - once I see it move from the piston coming up, I'll know I'm on the compression stroke and then I just stop the timing mark at 0 on the timing tab so that I'm at TDC, or at the very least in the good 'nuff vicinity of it.

As above, what's also important is, why did you have the distributor out? Did you replace it, or some part in it?

It's also important that wherever you drop the distributor, the rotor needs to be positioned fairly on point with one of the spark plug posts - that one being your #1, whichever you decide it to be. Typically for Pontiac engines, it's the rearmost one adjacent to the firewall, as that will give you the most room to twist the distributor in order to advance or r*tard the timing while you tune the engine.

[tinpusher]

All the above, I use 3/8 fuel one in the #1 spark plug hole , socket and ratchet on the center balancer bolt , rotate until the hose falls out and verify my timing marks on the balancer. Drop in the distributor making sure the rotor cap is pointing at the #1 spark plug wire.

[jbanna]

I'm certain I'm at TDC on #1 ( I used a pen in the hole and watched it move out, and can easily see the top of the piston), and also that the rotor was at the #1 position on the distributor cap; however, the timing mark on the balancer faces down, at the 6 o'clock position, about 100 degrees from where it should be.  Also, if it was on the exhaust stroke, then rotating the crank 180 degrees would just move move the timing mark 180 degrees right?

I've seen comments talking about the harmonic balancer slipping, but mine looks pretty firm...and yes, I did put the right plug wires in the right positions!

I pulled the distributor because the bronze gear had worn too much...

[b_hill_86]

Just for clarification, the phrase 180 out isn’t referring to being 180 degrees off, I would take it as “opposite of what you want” or something to that effect. So, yes, rotating the crank 180° would also rotate the balancer 180° but you’d theoretically be at bottom dead center.

If you are on TDC of the exhaust stroke the remedy would be to rotate the crank/balancer 360° to correct and now be TDC on the compression stroke.

I suppose if it were me I’d set #1 at TDC, mark the balancer at 0°, then set the mark at whatever your base timing is THEN stab in the distributor with the rotor pointing at the #1 plug terminal and see if it lights off. If so I’d think your balancer spun. If not, we’re missing something.

[tinpusher]

Just trying to cover all the bases,

The #1 cylinder is the first cylinder on the drivers side closest to the radiator. The reason why I want to make sure is that I had a Mustang 302  and didn’t realize they number their cylinders different….ran into the same problem.

Did you have the balancer removed, replaced or ? Is the key way in the crank/damper , I have seen it assembled without it, and the balancer only locked down by the crank bolt causing the damper to slowly rotate.

Did you verify the distributor gear was the correct one, and did you physically set them side by side? You removed the distributor because the gear was worn, so I’m assuming you replaced it.

Pontiac distributor rotor turns counterclockwise.

Not trying to seem rude , just trying to figure it out.

[jbanna]

I do know the cylinder numbers as I've had the car for 42 years; I need to review the stroke sequences to understand the 4 stroke concept; however, I did have compression when the piston reached it's highest point (besides the pen method, I also had a friend stick her finger in the hole and she felt plenty of compression). I also have had distributors out of my engines many times and have never had this difficulty before...after I get a handle on the 4 strokes I'll pull the distributor again and start over...I'm nearly certain the balancer has not slipped - I've had one do that in the past, and it was obvious, but if all else fails I'll try again disregarding the timing mark on the balancer and if it runs, either remark the balancer and plan a replacement; however, the balancer was new when I replaced the 403 with the 455, and only has about 20k miles on it. I only get about 5-10k on the bronze distributor gears because my roller cam is soft enough that a steel gear would prematurely wear the cam gear, which would be a much bigger headache!  Thanks for all the suggestions!!

[nUcLeArEnVoY]

Worse comes to worse, you can always pop off the valve cover and see if the #1 piston's valves are both closed. If they are, you'll know you're on the compression stroke.

[TA301]

Check out the link below as a reference.

https://www.youtube.com/watch?v=ExiPW3GNj2g

[jbanna]

Well, I found TDC and got the engine running, but the timing mark is more than 90 degrees away from the timing cover index, so it appears the balancer did slip, so I guess I'll go after that...ugh!  There are a lot of balancer choices with a wide range of prices...any recommendations?

[b_hill_86]

Glad you figured it out

[nUcLeArEnVoY]

Well, I found TDC and got the engine running, but the timing mark is more than 90 degrees away from the timing cover index, so it appears the balancer did slip, so I guess I'll go after that...ugh!  There are a lot of balancer choices with a wide range of prices...any recommendations?

For a stock or stock-ish application, I've heard the Powerbond balancers are pretty nice. You can try that, it's a direct bolt-in replacement.

[tinpusher]

What Nuclear said.. I purchased mine from Butler Performance.

[jbanna]

I decided on a Powerbond, but am having problems with aligning the woodruff key...are there any tips out there?

[tinpusher]

Maybe file the edges of the key, might be a little mushroomed. If it’s tight on the hub, I usually remove the key, get some fine sandpaper and clean up the crank . If it still tight, you can put dampner on a hot plate and heat it up a bit, should slide on after that.