If the pump has'nt work for sometime they maybe lockup, take off the side plate (8 bolts) and have a look inside to see if all are going up and down, if not work them with something like WD40 until they are working fine, unless you know what you are doing to the injector pump don'nt do anymore, take it into a service workshop...! hope this may help you, goodluck
arservices, October 2008