This has happened 3 times. After starting cold engine, engine dies and will not restart. Ignition timing is found to be about 15 degrees off. The timing gear has been found to be one or two cogs off on the timing belt. After re-timing, the car runs fine for awhile and then it happens again, even with new timing belt. Belt tensioner is OK.

Mechanic has pulled the distributor and oil pump and removed the shaft that drives them. This shaft is supported by 3 bearing in the block. The center bearing lubrication hole is open, but this bearing appears rough, other bearings look OK. Shaft journals appear OK. Mechanic thinks that this shaft periodicaly seizes for just a second causing the timing belt to slip a cog or two.

Has anyone out there experienced or heard of this problem? We need all the help we can get. Thanks.

I helped solve a similar problem in an '82. It would jump timing every six months, or so. The owner put up with this for years -- and would simply bring the car in for readjustment. I found a piece of plastic floating around the bottom of the timing belt cover but tucked way back under the lower sprocket. This chunk of plastic was maybe 1" by 1/4" and had a distinct impression of sprocket teeth in it.

Evidently it would now and then jounce around and sometimes wedge between the belt 'n sprocket. This apparently allowed the belt to slip on the lower sprocket, upsetting the timing. I have no idea why the timing belt never snapped.

Sounds like your mechanic is good but grasping at straws. Is the alignment pin between sprocket and I-shaft OK?

"Mechanic thinks that this shaft periodicaly seizes for just a second causing the timing belt to slip a cog or two..."

If the I-shaft siezed, even for a few seconds, the bearing surfaces should show some galling.