No spark when cranking over

Hope somebody here has some experiene of this and can help.
My problem is I have no spark at my plugs when the engine is cranked over on the starter. Strange thing is the spark is there when the distributor is turned by hand. I checked earth connections to body, coil etc. and still no start. Attached a timing light to a lead which only flashes when the engine turns without the starter engaged.
The engine was starting ok before i took it out to replace bearings and rings. I have a black wire with a loop on the engine and a male spade connector on the other that i can't find a home for so i guess this could be the cause of the problem. Appreciate any help!

Hope somebody here has some experiene of this and can help.
My problem is I have no spark at my plugs when the engine is cranked over on the starter. Strange thing is the spark is there when the distributor is turned by hand. I checked earth connections to body, coil etc. and still no start. Attached a timing light to a lead which only flashes when the engine turns without the starter engaged.
The engine was starting ok before i took it out to replace bearings and rings. I have a black wire with a loop on the engine and a male spade connector on the other that i can't find a home for so i guess this could be the cause of the problem. Appreciate any help!
Have you made sure that all your grounds are good, and that that is the only wire left?? Also have you pout full charge into your battery??

Thanks for getting back to me. The battery is fully charged and i tried running a separate cable to the chassis so i think the earth should be good. Also cleaned the earth cable running to the coil. Battery dropped to 10- 11 when cranking over. The cable i have left over is black, about 10 inches long and has a 1/2 inch loop one end and female spade on the other. Only place it seems to fit is the distributor but that has a connector from the main loom.

Another issue is with the cam timing, the FSM says to line up the dot on the crank and cam pulleys but the later has 2 dots marks on it and a kind or arrow which doesn't seem to point anywhere.
Also the belt i bought from Nissan has a solid line mark and a series of dots - does the dotted line go with the cam pulley dot?. Thanks

Is the ground wire at the distributor connected?? There is a black/white wire with a female connnector that is suppose to slip onto a male tab on the dist. unit itself near the base of it by the head.

Is your distributor ground wire bolted to the head?. Can anyone tell me why the cam pulley has 2 dots and what the pointer mark is for ? Thanks appreciate any help guys.

I had a similar problem with my turbo when I got it and just yesterday on the tadpole.

On the positive termial lead on the battery, there is a secondary lead. This connector gets a bit corroded and loose. Without it connected the car will turn over, but just never catch. Try wiggling it around while a friend cranks it over.

No.....the ground wire on mine slips on to a prong at the base of the distributor.....looking at the distributor, it around 10:00 give or take.
There are a couple of ground wires with ring terminals on the opposite side of the head that bolt to it.....think they are for the fuel injectors...but not 100%

Thanks guys for your help. I think i must have flooded the engine and the wet plugs were shorting out the sparks as the engine fired up after i heated the plugs with a gas torch after . Thanks again.