TR2/3/3A Timing

[RonR]

Folks,


Folks,
I had the distributer rebuilt on my TR3 by Advance Distributers.
I have spark at the points and at the plugs but the car will not start.
At times, it will backfire out the carbs.

I assume the timing is off.

I set the static timing by having No1 piston at tdc, the rotor pointing to No. 1 on the distributer cap, and the timing marks at the pulley and marker lined up. Then, using a 12 volt light, I rotated the distributer until the light just came on and tightened the distributer. I turned the adjuster knob on the side of the distributer 1/2 turn to advance 4 degrees. I am pretty sure this is how I have always set the initial timing.
But it will not start.

I pulled the distributer, rotated the crankshaft 180 degrees and reinstalled the distributer. Reset the timing, but it did not make any difference.

While waiting on the distributer to be returned, I replaced the front seal in the timing cover. I suppose I could have put the crankshaft pulley on 180 degrees off, but I thought there was a spline/grove alignment for mating the pulley with the crank so people like me could not get it wrong.

The timing chain and associated gears were not touched.

Any thoughts?
Thanks.

 

[Geo Hahn]

...I pulled the distributer, rotated the crankshaft 180 degrees and reinstalled the distributer. Reset the timing, but it did not make any difference...

You were thinking perhaps #1 was really at TDC on the exhaust stroke? That is what I thought too.

But the distributor only goes in one way so rotating the crank 180° does not change anything - unless you managed to jam the dog into place in spite of the offset of the slot.

This is how the drive on mine looks at #1 TDC compression (note that the slot is offset, thus the drive dog on the distributor shaft only fits one way):

This is how the dizzy looks in that same position:

If the slot is off then you remove the shaft and reinsert it into the correct position. It is something of trial and error as the helical gear causes the shaft to turn a bit as it engages so you have to allow for that to end up with the fitted shaft in the exact location.

Here is what the manual says about all this:

 

[CJD]

Backfiring out the carbs is, indeed, timing off.

You may have replaced the crank pulley assembly in the wrong orientation. It can go other than just 0 and 180 degrees. With a 6 bolt pattern it can also be off on 60, 120, 240 and 300 degrees.

At this point pull the #1 plug and ensure the piston is fully up at the 0 degree timing mark. Then pop the valve cover and ensure both #1 rockers are loose, also at the 0 degree mark.

 

[sp53]

I usually put my thumb over the plug hole when spinning the engine so the compression pushes it off showing that both valves are closed and piston is up, but you will have to fine tune that with the valve cove off to see the valves are both completely closed because it never stops perfect and you probably lost your datum point.