i have a 1994 mazda b2400 4cyl 2.3litre, it wont start when its warm,( ex id go to the store some back to the truck and it wont start i have to wait 15-20 min until it will eventually start) i think its most likely to be a timing issue, but i cant find where i can change the timing because the cam distributor cannot be adjusted. or if so how can i adjust the timing? and what is the advance on the timing?

thanks, ALEX.