The van has a new fuel pump, which pep boys told us that would get the van to turn or. it still is not working. can the spark plugs have anything to do with it not turning on. we have checked the fuses and they seem to be fine. now the switch that is in the rear of the van, does not seem to have any power. we had it tested and the light did not turn on.

I have heard about the cranck sensor coukd be the problem

Have you figured out if you are missing spark or fuel to make it stop running ?

Could b bad starter if motor won't turn over

You never take your vehicle to places like midas , pep boy's , firestone etc.. Find yourself a local independent repair shop . Po300 is a random misfire , not cylinder specific ! Causes ,lean air fuel mixture , vacuum leaks , low fuel pressure , clogged fuel filter , a O2 sensor problem . You need to find someone like this guy !
003 Scan Data for Fuel Code

thank obama for that it may be electric fuel pump and pickup in fuel tank. this has become very common since the intoduction of allowing a percentage of ethanol in our gasoline. it carries moisture with it which causes rust and the ethanol deteriorates any and all rubber seals hoses seals. if thats the cause tank must be droppeout cleaned pump and pickup replaced.$200 to $300. hopefuly not the prob.I would recomend checking coupons pep boys ,sears napa ect...they often offer free diagnostic test on vehicles. good luck.

as long as you can hear your fuel pump turning on when you turn the key on i would try changing the crank sensor. If you can't hear the fuel pump it is probably a computer problem.

TO MAKE YOUR ENGINE RUN YOU NEED AIR FUEL AND SPARK YOU SAY YOU DID YOUR PUMP BUT THIS PROBLEM SOUNDS LIKE FUEL RELATED

are you using a cheap fuel pump from a store like autozone, pep boys, or advanced? They sell cheap pumps, and always fail. The only way to stop the repair cycle is by an ac delco pump...

your pump wep hole, bad pump not pep boys fault :( sorry just need water pump.

i check to make sur ur fuel pump is working if you can hear running the i would try chevron techron injector cleaner and make sure ur spark plugs n wires r good