[Daniel Martinez]

Tengo el manual de taller de la chevy Astro, mismo motor, año 98. voy a verlo en y te subo la info.

Lo mejor que puedes hacer es traer manuales usados de USA, algunos están prácticamente nuevos y tienen toda la info del vehículo, lo del motor sirve para todos los motores iguales (Astro, Blazer, Silverado, etc), y son muy baratos, 6 a 15 USD.

Pa mientras, copy paste...

The P1345 code is that the distributor is out of phase,in other words not installed correctly, in order to phase the rotor for proper alignment, you need to bring the #1 cyl to top dead center making sure the crankshaft balancer marks line up with 0 on the timing tab located on the timing cover, when that is in line and cyl #1 is at top dead center, remove the dist and reinstall it making sure the rotor lines up with the index mark on the dist housing, the index mark is a V with a 6 stamped into the housing, now the dist drives the oil pump and you may need to rotate the pump drive shaft, i use a long flat blade screwdriver inserted into the hole the the distr was in and line the pump shaft with the dist, it'll take a little finesse to align it, just make sure when the dist is fully seated that the rotor lines up with the index mark.