Timing jumping

That looks like a factory type chain, and it is not a dual roller. If you have tried multiple distributors and the problem persisted, it is not a sheared pin, unless the oil pump is dragging enough to shear the pin of every distributor you put in it. So if the timing chain was indexed and installed correctly, the distributor(s) indexed and installed correctly without a sheared pin, then your problem is elsewhere, such as your firing order, coil, condensor, points, plugs, wires, cap, rotor, ignition module, ect.. Align the timing mark on the damper to the timing indicator and ensure the rotor is pointing to #1 cylinder on the distributor cap. Once that is done and the distributor is locked down, it should keep that orientation whether or not it starts. If after repeatedly cranking/running the engine the rotor orientation changes it is either the pin or chain. The chain can fail either by jumping a cog on the cam or crank gear, or the cam gear slipping, or the crank gear slipping. The gears slipping is very unlikely unless they were installed without the crank key or cam pin. If the chain is jumping and it jumps enough you can get bent valves and/or pushrods.

 

My plan
1) check distributor pin
2) coil was new, but will check resistances
3) verify firing order
4) verify TDC on compression stroke and check where the rotor is pointing

Maybe ill upgrade the distributor aasuming its not thr problem. Any recommendation?

 

You’re going on the assumption that the “mystery mechanic” did everything correctly.
IMHO it’s time to remove the front cover and check the cam, timing gears, chain and ALL associated parts.

 

My plan
1) check distributor pin
2) coil was new, but will check resistances
3) verify firing ordee
4) verify TDC on compression stroke and check where the rotor is pointing
5) then rip into everything

 

And i guess if i twar into its time to uogeade everything i can. Anything I should start looming at getting or measure?

This will be my first time doing this

 

I,d suggest getting help from rebuilder. You did say motor is recently rebuilt.

 

Good news! Got the car back in my life... Did all the damage control, got rid of rodent nest's and all.

Soaked the cylinders in mystery oil and freed them up and it rotates now.

Bad news.... Coolant in the oil pan when it went to change oil.... Any other options to look at before pulling the head?

Thanks

 

Coolant in the pan can be, at best head gasket, at worst cracked head or block.

 

Yeah I pulled the head. I dont see any obvious cracks in either. The gasket was a classic inlines metal gasket that sat there for about 7 years. Woulsnt be surpirses if it rusted through

 

Inspect gasket and heads. Should be some tailtale sign if failed. Take pic and post if u need help.

 

Well!!!! My streak ended. Last week my timing jumped in f100 with 429.

 

Cracks can be very, very hard to see, impossible basically unless you have a machine shop magnaflux the part.

 

So pulled the head... It rotates by hand now but this concerns me. Soaked it in mystery oil for a day or two