1983.5 1.9 wbx.

Last fall I had a "won't start" situation. Had it towed to the local
VW specialist who installed new plugs, HT leads, dist cap, cleaned up
grounds etc tuned it and got it running. I drove it home and parked
it for the winter. Went out yesterday (after charging the battery)
turned the key, listened to the fuel pump hum as normal (2-3
seconds), turned to start position, it cranked, fired and stopped.
Retried and no fire.  I've removed and replaced ("cleaned") the temp
2, and coil connectors, added a booster battery.  It cranks well but
does not fire.  Yes there is gas. Gauge reads half full.

Suggestions as to what to look for?

TIA
Don