B234 DOHC 16 valve non-turbo engine, 214k miles, automatic, owned 7 yrs ran normally through Wednesday night. Thursday morning cranks normal but no start, not one pop even when spraying ether in the intake hose at the air filter box and pouring HEET in fuel tank. In between snow storms I have done the following: checked spark at plug wires with a spark tester ok; took apart fuel pump relay cleaned contacts tested good; checked all fuses ok; cleaned inside dist cap & rotor; replaced spark plugs with new Bosch #7900 Yttrium Cu core; checked fuel at pressure regulator pumps out into container ok when cranking; can hear injectors clicking; took intake hose off and sprayed ether into throttle body while cranking again no pop; pulled new plugs and checked all are sparking; poured a little gas into plug holes and put plugs in again no pop; OBD LED light indicates code 1-1-1 no faults; replaced main fuel filter; jumpered across fuses 1 & 11 and can hear main pump working and hear a gurgling splashing sound in the fuel filler neck; tested sealed black relay on RF fender good; jumpered across 2 larger wires at this relay no difference; ground on RF fender pulled off spade connectors and pushed on again no difference; checked timing belt ok timed correct has not jumped a tooth; found balance shaft belt is broken; tested sealed green relay on LF fender no clicking.If the sun comes up and it stops snowing this morning I will try the in-tank pump and filter sock.All I've found wrong is the balance shaft belt and the green relay but can they cause non-firing? What does that green relay do?BTW I appreciate the 700 FAQ and have printed out the OBD and fuel system sections.