Distributor Timing

[Ed D.]

I pulled the distributor on my 1965 327/300 to replace the tach gear. The engine ran fine before I did this. The distributor does not have points but has a electronic conversion (one wire).
I put the engine to TDC aimed at plug one on the distributor cap and dropped it in. The engine started but under way there is little power I tried retarding and advancing . Engine still runs poor regardless.
I pulled the distributor again with similar results (slightly better power ...but still not right)
QUESTION... Can the engine be running and be off by just a tooth on the distributor ? ....and cause this poor performance? With the timing light the marks seem to be just about where they used to be.
My next step is to pull out the distributor again and repeat and repeat until I get it I may install a new cap and rotor but don't see how that could help since everything ran well before! On the bright side ... my tach now works ...LOL
....ANY IDEAS ?????

[Edward J.]

Re: Distributor Timing

Ed are you setting the timing with the vacuum advance hose off and plugged? If you were off a tooth when you install timiing light onto running engine the timing could not be set on a C2 because theres not enough rotation possible of the distributor. it would hit the intake or coil bracket.

If you have the #1 plug out and on compression stroke, the mark on balancer is at TDC and dist. rotor is pointing to no.1 . you should be right. mark sure your firing order is correct. in case you mixed up a wire. another thing I have seen before is sometimes things get changed around on the dist cap because some one rotated the wires on the dist. cap because they were a tooth off. this will screw you up.

[Michael W.]

Re: Distributor Timing

I'd like to choke the guy that first came up with the 'one tooth off' story as much as I'd like to throttle the guy that thought neck ties were a necessary part of office dress. I'd never heard of such a thing until the Corvette Forum came along............

Ed- if you've got the timing light on #1 cylinder and the distributor can be rotated to adjust the timing to the desired setting, it cannot be 'one tooth off'.

[Ed D.]

Re: Distributor Timing

I did not disconnect the vacuum hose and plug with success. . With vacuum on the engine ran smooth at idle. Just no power when driving. At first I tried to disconnect vacuum line and block.... engine hardly idles at low speed.
Reading between the lines the vacuum line must be off and blocked to set timing. Since the engine hardly runs doing that .... then do I need to find TDC and start over?

[Ed D.]

Re: Distributor Timing

Mike.... I will go over the wiring to double check!

[Michael W.]

Re: Distributor Timing

.. then do I need to find TDC and start over?

No. Adjust the timing with the vacuum disconnected and plugged on the manifold (not the distributor). Keep the engine at stated hot idle speed throughout.

[Terry K.]

Re: Distributor Timing

[Joe L.]

Re: Distributor Timing

I am NOT any kind of expert on this stuff, but I chased a similar issue after removing and re-installing a distributor on my 60 driver. Mine had an “Ignitor” unit to replace the points; and I had inadvertently bent the bracket that holds the magnetic pickup unit. With the magnetic pick up gap way way too large, timing adjustments were useless……

Terry-----


I also think that Ed's problem is somehow related to "something that went awry" with the electronic conversion unit when the distributor was removed or re-installed.

[Duke W.]

Re: Distributor Timing

I'd like to choke the guy that first came up with the 'one tooth off' story as much as I'd like to throttle the guy that thought neck ties were a necessary part of office dress. I'd never heard of such a thing until the Corvette Forum came along............

Ed- if you've got the timing light on #1 cylinder and the distributor can be rotated to adjust the timing to the desired setting, it cannot be 'one tooth off'.

Take any C2 small block with a properly indexed distributor. Pop is out and reindex it a tooth off in either direction.

Now try to set the timing.

Some engine configurations may be able to tolerate being a tooth off depending on how much rotational freedom the distributor has , but NOT C2 small blocks. There is ONLY ONE way to index it to the camshaft and be able to achieve the correct initial timing, PLUS the distributor drive gear dimple MUST be aligned with the rotor tip.

Duke

[Joe L.]

Re: Distributor Timing

Take any C2 small block with a properly indexed distributor. Pop is out and reindex it a tooth off in either direction.

Now try to set the timing.

Some engine configurations may be able to tolerate being a tooth off depending on how much rotational freedom the distributor has , but NOT C2 small blocks. There is ONLY ONE way to index it to the camshaft and be able to achieve the correct initial timing, PLUS the distributor drive gear dimple MUST be aligned with the rotor tip.

Duke

Duke-----


Yes, but if I'm reading the original post correctly (i.e. "With the timing light the marks seem to be just about where they used to be"), it would seem that he does have the proper initial timing.

[Duke W.]

Re: Distributor Timing

I did not disconnect the vacuum hose and plug with success. . With vacuum on the engine ran smooth at idle. Just no power when driving. At first I tried to disconnect vacuum line and block.... engine hardly idles at low speed.
Reading between the lines the vacuum line must be off and blocked to set timing. Since the engine hardly runs doing that .... then do I need to find TDC and start over?

Get the timing light set up and loosen the distributor so you can turn it by hand with some effort- not completely loose. Start the engine. Disconnect and PLUG the VAC signal line. (A golf tee is the special tool I use for this task). Use the idle speed screw to establish a stable idle at the lowest possible speed - no more than 500 - and set the initial timing. Once set, slowly increase engine speed until you see the timing mark advance. If it does above the speed you set the timing, okay. If not, the centrifugal has started and you must get the engine speed lower to set the initial timing.

Once the initial timing is set and verified with the distributor tightened down, connect the VAC and go through the idle speed/mixture adjustment procedure in the 1963 Corvette Shop Manual.

Duke

[Gerard F.]

Re: Distributor Timing

Ed,

The timing light only measures the position of the #1 cylinder. If you have some of the other plug wires at the distributor in the wrong positions, it will surely run lousy.

Maybe do a check of all the plug wires, position as well as resistance/continuity. Just a thought.

[Dennis O.]

Re: Distributor Timing

Another possibility. In the 25 years I have owned my 2 small block cars ('67 and '68), I have had to have both harmonic balancers rebuilt because they had "slipped". It's worth checking to see you have the timing marks in the correct place.

[Richard C.]

Re: Distributor Timing

dist gear 180 out? the dot on the gear has to line up w the roter tip?

[Michael W.]

Re: Distributor Timing

dist gear 180 out? the dot on the gear has to line up w the roter tip?

This only becomes of importance if the distributor housing cannot be rotated sufficiently to achieve the desired timing.