hi. I've got an '89 ranger with a 2.3l engine with a distributorless ignition system. The truck was running fine the last time I drove it. However, when I started the truck this time and drove it, it was running rough. It felt like it was going to stall when I stopped and didn't have much power when I accellerated. It seemed like it was running on 3 cylinders. I think the time belt might have slipped but I'm not sure how to check for that. If it has slipped can someone please tell me how to adjust it?

If it's not the timing belt being off could it be something like a vaccuum hose or a pvc valve not working properly? If anyone can be of any help to me, I'd greatly appreciate your input. Thanks.