Not getting full timing advance

[echrisconnor]

I'm having some timing issues. The dwell has been set with a dwell meter and is right in range. I time to car to 5deg ATDC per specs for a C3 and everything is great. However, when I go to do the full timing advance check at 6000, I'm only getting about 25 deg of advance. This is the same regardless of vacuum line hookup.

So, what do do? Could it be a stuck weight in the dizzy (it's well lubed and not corroded at all, but I haven't opened it up)? Should I just set the maximum advance and not worry about the idle setting?

One thing to note is that in order to time the car, I need to rotate the dizzy as far as it can go in it's range. I've re-indexed it too, but then I'm at the opposite end of the range. Does the rotation position effect how far it will advance?

[911pcars]

You should be getting between 30-35º of total advance (distributor + initial setting measured at the crank pulley). How are you computing total advance? E.g. 5º ATDC + 25º BTDC = 30º?

If you're running out of physical room rotating the dist. housing, you could be a tooth off. Starting with the rotor pointing to the notch in the housing (use as a reference point), remove the distributor and re-engage it one gear tooth more in the normal rotation direction, then realign the notch on the housing with the rotor as a rough starting point for setting timing. Fine tune with your timing light. Don't exceed max. factory advance specs @ 6k rpm.

Many owners disable the vacuum retard as it's merely there for idle emissions, but it makes the engine run a little warmer at idle. As soon as the throttle is brought to off-idle, the retard mechanism should revert to normal advance mode.

Sherwood

[echrisconnor]

Well, maybe I'm getting a total of about 30deg advance then... if you figure 5 deg ATDC to 25 deg BTDC. I'm estimating that getting to 25 degrees BTDC by the fact that I'm a little over 2/3 of the way to the of the 30/35 deg mark at 6k. I don't have a light that you can dial in specific settings on, but my concern, of course, is that at 6000, I'm not reaching the full 30 - 35 deg.

As for the physical rotation room, I've already done the re-indexing thing moving back a tooth, but one tooth seems to translate to putting it at the opposite extreme. If needed though, I can swap things around and get more total advance.

So, should I be content that I'm getting about 30 degrees advance out of the dizzy, and just time it for total advance and not worry about the setting at idle?

[911pcars]

"So, should I be content that I'm getting about 30 degrees advance out of the dizzy, and just time it for total advance and not worry about the setting at idle?
"

I should correct myself a little. The vacuum mechanism retards the timing only at idle or when the throttle is closed (again for emissions purposes). Thereafter, it defaults to whatever the initial static timing was set at (distributor position, usually 5ºBTDC) + the advance created by the advance mechanism.

Just as you said, set it for the correct total advance at 6k and you'll be fine (or at least, to factory specs). If you disconnect the vac. retard hose, you may have to reset the idle speed as it'll rise a little due to the extra advance.

Sherwood

[echrisconnor]

Got it figured out. The problem was that the vacuum retard wasn't working properly. The vacuum port I was plugged into wasn't drawing anything, so I was getting neither retard to the distributor, nor leaning at idle through the WUR. Plugged into a different port and am now in business. Still not sure why I wasn't getting vac. through that port, since it's the right one, but may be blocked.

So, that seems settled, although I do have a new problem which I'm about to post about hesitation at high-rpms and high-altitude.

Thanks,

chris

[Bill Verburg]

As you know flatland mixtures at altitude are too rich, has the mixture been set for your area and gas?

[echrisconnor]

Well since I haven't created a new post yet...

My mixture has been set without a meter. I've used the lift/lower the throttle plate method and gotten it to a point where it seems reasonably happy.

What happened, was I drove my car up from where I live, at about 5000 feet, to a friend of mine's house at about 8000 ft. We took the car out for a spin, and headed uphill from there. At about 5500 revs, the car started to hesitate/almost cut out and loose power. It was very unhappy revving to 6500. At first, it almost seemed like a rev-limiter thing, or electrical cutout. Then, after taking the car back down the mountain, the problem went away. So, I assume it's a mixture thing, with the mixture going overly rich at altitude.

[Paulporsche]

Chris,

Are you sure your WUR is set correctly?
Also, do you have a good vac line attached to it?
Some WURs have an additional ability to adjust for high altitude. Does yours?
Did you try the push/pull method 2 the higher altitude?
Is everything else OK, like points(?) plugs, wires, rotor, distributor?

[echrisconnor]

A couple months ago, I did a pressure check on my fuel system. The WUR was adjusting cold and warm control pressures appropriately, and was leaning the mixture (increasing control pressure) with vacuum. I did not do a set of checks with the car running though. I also have tested the injectors for good spray and volume.

At altitude, I did the lift/depress the plate test, and it seemed to be happy.

The WUR is now on the same vac line as the dizzy, and is getting vac draw at idle and I assume leaning the mixture.

Points are new, dwell is set properly with a meter, wires are good, and dizzy I believe to be in good order.

I've had the car running rich before, and never had it cut out at high revs like that. Any other ideas why it would cut out like that?

[Early_S_Man]

Chris,

I believe the C3 has the same distributor specs as the 2.4E engine, and consequently, the same advance curve. My suggestion would be to put a timing light on it and check the advance curve from idle to 6200 rpm. The following graph and chart should be compared to your findings:

[echrisconnor]

What would too much advance feel like? I'd just changed the timing and checked the advance up to 6000, but based on the diagram, it looks like this dizzy will keep advancing past 6000. Since I was getting this funky high-rpm cutout/bucking at high altitude and very heavy load, I wonder if that was the problem -- not the mixture?

[}{arlequin]

mine is acting up as well, doesn't keep regular values. It looks like it may be time to clean some of the distributor internals just to make sure. Good topic. Going to keep tabs on the developments.

[oneblueyedog]

Maybe your advance plates on the Dist. are frozen/ rusty?

[echrisconnor]

I don't think anything is frozen. The full advance issue is now resolved since I got the vacuum retard working properly. The issue was that the vac hose wasn't drawing vacuum and therefore the idle setting was off and wouldn't advance enough. With the vac retard working and the timing re-set, we're in business.

Now the issue may be that I'm either getting too much advance -- or my mixture is off. See above about high altitude/rmp flatering.

Not sure if I'm too rich, or possibly too far advanced now. I'm going to re-check timing at 6200 based on Warren's diagram.

The timing does fluctuate when timing it though -- is this normal? It bounces around by 3-5 degrees especially at idle. Is this a sign of a worn dizzy?