If oil is inside the distributor then the internal oil seal is bad. I don't think that replacing either of the O rings visible when you pull the distributor will correct a leak to the distributor insides. I have heard of sources for this seal but cannot remember where.

It would be important to know if you have spark at coil. This will tell you if problem really is in the distributor or not.

Good luck

Once you are getting spark again, and it still will not start. Remove the plugs. They are probably wet with gas from all that cranking. This can prevent them from sparking, and hence no start. Either blow them dry, or replace them if they have some age on them. They are cheap enough in the sceme of things. I learned this the hard way last winter.

The connector and wires(Not spark plug or coil) that attach to the distributor are very fragile. Its common for the connector to go bad.

Check it out, good luck.

No...just replace the O rings around the distributor. It's pretty difficult to disassemble the distributor to replace the third O-ring (although i understand it can be done, be careful not to bend the shaft when driving the pin out...the O-ring is unobtainium volvo but there is a Honda O-ring that fits) and most leaks are O-ring associated without the internal O-ring being the cause. Just replace the rotor and cap.

I don't know if there's a Hall sensor in the 90 non turbo 740 engine...check your manual or the FAQ. Check if you have spark at the coil before hooking up to the new distributor.

good luck. Strange there's no codes.....