1989 voyager...HELP!!!

My boyfriend and I have a 1989 Plymouth Voyager and it WAS a very reliable car, until now. We have no idea what is wrong with it, it left him stranded on the highway and we finally got it home. We replaced the plugs, wires, distibutor cap, rotors, and some sensor and it still wont start. It wants to start really bad but it wont. It drained the battery from trying to get it started. It has spark, he tried the computer test thing and it gave him code 34 and that is the speed control sensor and that will not stop it from running. I thought at first he may have missed counted but he didn't. We have no idea what is wrong with it and as of right now he cant work because of it. Please if there is any advice anyone has PLEASE HELP!!!

Clogged fuel filter, bad fuel pump, or even a stretched or broken timing belt come to mind.

I'm no expert, but I've owned six of these Caravans. Good luck.

Code 34 relates to your EGR system. You may have a bad vacuum hose or the EGR valve unit is inoperative.